ProfitPress Mega CDROM2 …eeware (MSDOS)(1992)(Eng)/ProfitPress-MegaCDROM2.B6I/APPS/STATISTI/ESDISK.ZIP/EASISTAT.DOC

Text File | 1989-02-22 | 115.2 KB | 3,453 lines

                                 EASISTAT.DOC

                    On-disk documentation for EASISTAT v. 1.01
                     Copyright (C) ARC Scientific Limited 1989


       1    BASIC INFORMATION                                   1
       1.1  Limitation of liability                             1
       1.2  The shareware concept                               1
       1.3  User support                                        3
       1.4  Specifications                                      4
       1.5  Overview of the manual                              5
       1.6  Other Shareware programs                            5

       2    GETTING STARTED WITH EASISTAT                       6
       2.1  Demonstration                                       6
       2.2  Quick start                                         7
       2.3  Installation                                        8
       2.4  Screen layout                                      13
       2.5  Keyboard input                                     14
       2.6  Description of files used by EASISTAT              14
       2.7  Editing files                                      15
       2.8  Drawing graphs                                     16

       3    COMMAND SYNTAX                                     17
       3.1  Selecting a function                               18
       3.2  Command options                                    19
       3.3  Referring to rows and columns                      20
       3.4  Logical expressions                                21
       3.5  Arithmetic expressions                             23
       3.6  Operator precedence                                24
       3.7  Combining arithmetic and logical functions         25

       4    DATA MANAGEMENT FUNCTIONS                          26
       4.1  Edit                                               26
       4.2  Titles                                             28
       4.3  List                                               28
       4.4  New                                                29
       4.5  Delete                                             29
       4.6  Label                                              29
       4.7  Format                                             30
       4.8  Derive                                             30
       4.9  Sort                                               31
       4.10 Narrow                                             32
       4.11 Widen                                              32

       5    STATISTICAL FUNCTIONS                              34
       5.1  Basics                                             34
       5.2  Chi-squared                                        35
       5.3  Wilcoxon's rank sum                                36
       5.4  Kendall's rank correlation coefficient             36
       5.5  Kolmogorov-Smirnov test                            37
       5.6  T test                                             37
       5.7  Linear regression and correlation coefficient      38
       5.8  Anova                                              39
       5.9  Multiple regression                                39
       5.10 Component analysis                                 40





       6    FILE MANAGEMENT FUNCTIONS                          42
       6.1  Data                                               42
       6.2  Output                                             43
       6.3  Input                                              44
       6.4  Log                                                44
       6.5  Echo                                               45
       6.6  Pause                                              45

       7    SPECIAL FUNCTIONS                                  46
       7.1  Help                                               46
       7.2  System                                             46
       7.3  Screen                                             46
       7.4  Arithmetic                                         46
       7.5  Quit                                               47

       8    ERROR MESSAGES AND BUGS                            48
       8.1  List of error messages with their meanings         48
       8.2  What to do if you get an error message             48
       8.3  Running out of memory                              48
       8.4  Bugs and crashes                                   49

       9    ACKNOWLEDGMENTS                                    52

            Order and invoice forms on back pages





                               EASISTAT.DOC

      Chapter 1                BASIC INFORMATION

      This documentation is copyright. It may only be reproduced, stored or
      transmitted in whole or in part by any electronic or mechanical
      means in accordance with the conditions outlined below.

      The documentation contained in the file EASISTAT.DOC is an extract
      from the printed manual which is available to registered users.
      Where sections of the manual have been omitted the following symbol
      occurs:

                                    * * * * *

      It is hoped that this incomplete documentation will be adequate to
      provide some idea of the facilities available from EASISTAT, and
      enable the program to be used for evaluation purposes. However
      people who find the program useful are encouraged to pay for it
      (current price thirty pounds inclusive of VAT and delivery charges),
      thus becoming registered users. Registered users receive an up-to-
      date version of the program and a full printed manual.

      1.1  LIMITATION OF LIABILITY

      It is possible that this manual or the EASISTAT program contain
      errors which mean that the program does not behave in the way
      described. We have attempted to the best of our ability to
      eliminate such errors, but it is possible that some do exist. If the
      software or manual contains significant errors rendering the program
      unusable then our liability is limited to replacing defective
      material that we have supplied or refunding the purchase price paid.
      No liability can be accepted for anybody who has not paid for the
      program and become a registered user. In any event the liability of
      ARC Scientific Ltd. with respect to problems associated with the use
      of this program through such errors or through other circumstances
      shall not exceed the price of the program as published by ARC
      Scientific Ltd. or as paid by the user, whichever is the lower. Use
      of the software supplied constitutes an understanding and acceptance
      of such limitation of liability.

      1.2  THE SHAREWARE CONCEPT

      One way for the programmer to distribute useful programs to users
      is through ordinary retail outlets - shops and mail order companies.
      This demands high overheads for many middlemen and forces up the
      final price of the program to the user. In addition the user must
      pay for a program before he acquires it, usually having to judge its
      merits second-hand by means of a review or advertising copy.
      Programs acquired in this way are normally copyright and it is
      forbidden and illegal to copy them. Often they are in fact copied
      illegally, forcing up prices further, or else the distributor is
      obliged to apply some form of copy-protection to the program which
      reduces its convenience of use.

      The Shareware alternative is to allow individuals to copy a program

                                    1




                               EASISTAT.DOC

      freely and to encourage them to pass it on to their friends and
      colleagues. The program remains copyright but the holder of the
      copyright grants restricted permission to individuals in possession
      of the program to make copies of it. Potential users can evaluate
      the program first-hand and are only then requested pay for the
      program if they decide that it is worth the price asked for it.
      Because of the low distribution costs the price for a Shareware
      program can be many times lower than for an equivalent program sold
      conventionally. No legal sanctions are applied to somebody who uses
      the program without paying for it, but the success of the Shareware
      concept depends on those people who do feel it is reasonable to pay
      for something which they find useful. In the case of EASISTAT people
      who pay for the program will be added to the list of registered
      users and will receive a full printed manual, of which this on-disk
      documentation is an extract.

      THE SHAREWARE AGREEMENT

      You are assumed to understand and accept the following conditions
      as a condition of your possession and use of the EASISTAT program
      and associated files.

      EASISTAT is distributed as a Shareware program. That means that you
      are legally allowed to copy it and give copies to other people who
      you think might like it - in fact you are encouraged to do so.
      However please note the following points:

      1. The copyright of the program remains with ARC Scientific Limited.

      2. You must not charge more than a nominal fee for the program if you
      pass it on to someone else, nor may you distribute the disk as part
      of a promotional scheme.

      3. Please acknowledge the program in any publications of work for
      which it was used.

      4. If you pass it on you must do so in unmodified form and the
      following eight files must all be passed on together:

          EASISTAT.EXE
          EASISTAT.DOC (This file)
          EXAMPLE.DAT
          DEMO
          DEMO.BAT
          READ.ME
          ORDINV.PRN
          PRODUCTS

      5. The printed manual is copyright and may not be reproduced or
      transmitted in whole or in part without the express permission of
      ARC Scientific Limited. If the disk files are passed on to another
      user, they must not be accompanied by additional documentation which
      could wholly or partly take the place of the printed manual.


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                               EASISTAT.DOC

      6. Although the program may be freely copied and may be used for
      evaluation purposes, anybody who thereafter continues to use it
      should pay to become a registered user. Registered users will
      receive an up-to-date version of the program and the full printed
      manual.

      The current price to register EASISTAT is thirty pounds sterling,
      which is inclusive of VAT and delivery charges in the UK and
      is inclusive of shipping charges for overseas orders. The price
      for orders from the US is fifty-five US dollars inclusive of
      shipping. These prices are correct at time of writing, but are
      liable to change without notice.

      Please address orders and enquiries about bulk discounts to:

         ARC Scientific Limited,
         257 Woodstock Road,
         Oxford OX2 7AE.

         Tel. [phone]

      Order and invoice forms are provided at the end of this
      documentation.

      If you give the program and the seven other files that go with it
      to someone else then please explain to them how to set the
      demonstration running. If you give them a floppy disk with the
      eight files on we recommend that you write on the label:

      EASISTAT Copyright (C) ARC Scientific Ltd. 1989

      Enter -     A:
                  DEMO

      1.3  USER SUPPORT

      User support is limited to those people who have paid to become
      registered users.

      Because of the low price of this program we are able to offer only
      limited user support. If you have problems running EASISTAT then
      please consult the manual carefully to see if that can help. If you
      still need advice then please write with a stamped addressed
      envelope to:

      EASISTAT User Support,
      ARC Scientific Limited,
      257 Woodstock Road,
      Oxford OX2 7AE.

      We will attempt to answer your query as quickly as possible,
      though we cannot guarantee to be able to do so. Please give us



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                               EASISTAT.DOC

      full details about the following information:

      Your DOS version number.
      The version number of EASISTAT.
      The type of computer and peripherals you have.
      The names of any memory-resident programs.
      The contents of your AUTOEXEC.BAT and CONFIG.SYS files.

      Please enclose a copy of any relevant data files and command
      files on a floppy disk. We will return it.

      1.4  SPECIFICATIONS

      Almost all the statistical functions implemented in EASISTAT are as
      described in Statistical Methods in Medical Research by P. Armitage
      and G. Berry (2nd edition, Blackwell Scientific Publications, 1987).
      The user is advised to consult this source for a detailed account of
      the theoretical basis of the tests and the circumstances under which
      they should be used. It is assumed that the user has at least a
      basic knowledge of statistics, and only brief descriptions of the
      tests will be given in this manual, which does not replace a
      statistics textbook.

      The probability values given are two-tailed for tests based on the t
      distribution, and one-tailed for tests based on the normal
      distribution. In practice this means that sometimes you may want to
      double the probability value given for some of the tests based on
      the normal distribution (ie halve its significance), depending for
      example on whether or not you had a prior hypothesis for the
      direction of the difference. Or can you just quote the result, say
      it is one-tailed and let people draw their own conclusions. The
      probabilities given for the chi-squared and F distributions are the
      conventional one-tailed ones, which are almost always what you want.

      EASISTAT runs on a personal computer using MS-DOS version 2.0 or
      later. It requires at least 256K of memory, but will use more if
      available. All data is held in memory for speed of calculations, so
      the amount of data which can be processed is limited by the size of
      the computer's memory. With 640K of RAM EASISTAT will accommodate
      over 70,000 data points, though this figure is reduced if there are
      very many rows and very few columns. The maximum length for a line
      read in from a data file is 5,000 characters (not columns). The
      maximum number of columns is about 1,300 and the number of rows must
      not exceed about 10,000. The maximum length for command lines read
      in from a file is 240 characters. Lines read from the keyboard are
      limited by the screen width to 76 characters. Values are stored as
      single precision floats and operations are carried out in double
      precision. Values stored in a data file are only stored on disk to
      the precision with which they are displayed. Multiple regression and
      principal component analysis need about as much extra memory as is
      occupied by the columns analysed.

      If a maths coprocessor chip is installed then EASISTAT will use it
      to increase the speed of calculations. EASISTAT will run in a text

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      window of DESQview in background or foreground and will run under
      Microsoft Windows if the "Writes directly to screen option" is
      selected from the PIFEDIT menu.

      1.5  OVERVIEW OF THE MANUAL

      You should begin with the next chapter on "Getting started with
      EASISTAT". You will probably wish to see the demonstration if you
      have not done so already, and then you should carry out the
      installation procedure described. You should look through the
      chapter on "Command syntax", but you will probably wish to study
      this properly at a later date. Assuming that you do not already have
      data which you wish to analyse you will first have to enter some
      data using the EDIT function described in the chapter on "Data
      management functions". When you have entered your data you will wish
      to save it on disk, and this is done using the DATA SAVE function
      described in the chapter on "File management functions". Then you
      may try out any of the other functions described in the rest of the
      documentation. As you become more familiar with EASISTAT you should
      make an effort to familiarise yourself with the use of command
      files, and perhaps with the more complex arithmetic and logical
      functions available.

      1.6  OTHER SHAREWARE PROGRAMS

      Two other Shareware programs are recommended in their own right and
      are especially useful for users of EASISTAT. PC-Write is a word
      processor which can be used to edit EASISTAT's auxiliary files, and
      PC-File:dB is a database which comes with a graph-drawing program
      called PCG2 which can draw graphs from EASISTAT's graph files. They
      are obtainable as Shareware from a number of user groups and
      Shareware libraries which advertise in magazines dealing with PC's.
      Both are available to members of the IBM PC User Group:

      The IBM PC User Group,
      PO Box 360,
      Harrow HA1 4LQ,
      UK.

      Registered copies of PC-Write cost 89$ from:

      Quicksoft Inc.,
      219 First Avenue N #224-BYTZ,
      Seattle, WA 98109,
      USA.

      Registered copies of PC-File:dB cost 89$ from:

      ButtonWare, Inc.
      P.O. Box 96058
      Bellevue, WA 98009,
      USA.



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                               EASISTAT.DOC

      Chapter 2         GETTING STARTED WITH EASISTAT

      2.1  DEMONSTRATION

      If you do not want to see a demonstration of EASISTAT in action then
      skip this section.

      2.1.1  Starting the demonstration

      On the disc supplied there is a special command file called DEMO
      which has been written to provide a demonstration of some of
      EASISTAT'S features. The demonstration lasts a few minutes. To see
      it, first make sure that your computer is turned on and that you
      have booted up DOS in the usual way (if you do not know how to do
      this please consult your DOS manual). You should see a prompt saying
      something like eg A> or B:\> or C:\DOS\>. Put the disk supplied into
      the disk drive of your computer and close the door of the drive. Do
      not take the disk out of the drive until the demonstration has
      finished. Now type the name of that drive followed by a colon
      (either A: or B:) and press the ENTER (or RETURN) key. Now type DEMO
      and press the ENTER key. The demonstration should begin.


      2.1.2  During the demonstration

      The demonstration will pause occasionally to allow you time to read
      what is on the screen. When a pause occurs the following message
      appears in the bottom window of the screen:

        A pause has occurred in the input command file

       'E' to end file, 'K' to use keyboard, any other key to continue

      When the message appears the computer will wait for you to press a
      key before it does anything else. If you press any key except E or K
      the demonstration will continue normally, and we advise you to do
      this. If you press E the demonstration will finish prematurely and
      you will be left with control of the EASISTAT. To find out what to
      do next see the section titled "When the demonstration finishes". If
      you press K then you will gain temporary control of EASISTAT and you
      can issue any commands you like to it as described later in the
      manual. You can then return to the demonstration at any time by
      entering INPUT CLOSE.

      Sometimes the demonstration may appear to have paused but the above
      message does not appear in the window. This means that EASISTAT is
      busy performing a calculation which is taking a little time. The
      longest takes about a minute on slower computers. Just wait and the
      demonstration should proceed.

      Do not worry about the other words you see popping up in the bottom
      window. These are requests by the program for new commands and
      parameters, but they are supplied by the demonstration file so you
      do not have to do anything.

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                               EASISTAT.DOC


      2.1.3  When the demonstration runs the editor

      Late on in the demonstration the data editor is displayed and you are
      left in control of it. For full details of how to use the editor you
      can refer to the section specifically on that subject. For
      demonstration purposes you may just want to move around the table a
      bit using the cursor keys and changing a few numbers here and there.
      The only thing you really need to know is how to leave the editor.
      To do this simply press the ESCAPE key, which is usually up near the
      top left of the keyboard and is marked "Esc". You will return to the
      end of the demonstration.

      2.1.4  When the demonstration has finished

      At the end of the demonstration you will be put in control of
      EASISTAT (if you have paid for the program then obviously you should
      ignore the message asking you to do so). The rest of the manual
      describes how to use EASISTAT, but for now all you need to know is
      how to quit the program and return to DOS. To do this type QUIT then
      press the ENTER key, then when asked if you are sure type YES and
      press ENTER.

      We recommend that when you have become a bit more familiar with
      EASISTAT you should study the file called DEMO carefully. You can
      read it with a word processor or you can print it out on a printer
      by entering PRINT DEMO when you are at the DOS prompt. It is simply
      an EASISTAT command file such as you can write yourself, and it may
      be very helpful for you to see the way that the commands have been
      typed in the file to create the demonstration that you see.

      2.2  QUICK START

      You are advised to skip this section and move on to the section
      headed "Installation". However if you can't wait and want to have a
      have a go at working EASISTAT here's what you do:

      1. Make sure your computer is turned on and that you have booted up
      DOS in the usual way (if you do not know how to do this please
      consult your DOS manual). You should see a prompt saying something
      like eg A> or B:\> or C:\DOS\>. Put the disk supplied into the disk
      drive of your computer and close the door of the drive. Now type the
      name of that drive followed by a colon (either A: or B:) and press
      the ENTER (or RETURN) key.

      2. Type EASISTAT and press ENTER. The EASISTAT screen should appear.

      3. Press any key, and the message "Select function -" will appear in
      the bottom window. In the top window a list of all the functions
      available appears.

      4. Type EDIT and press ENTER. You are now looking at the data editing
      screen, which is almost empty except for one column called "NEW" and
      one row with a zero in it.

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                               EASISTAT.DOC


      5. Hold down the CONTROL key (marked "Ctrl") with one finger and then
      while doing so press the RIGHT ARROW key. A second column appears to
      the right of the first one. Do this once or twice more if you feel
      like it.

      6. Using the arrow keys you can move from column to column and then
      type a number into that column. To make a new row and move down to
      it press ENTER.

      7. Moving around the screen in this way type in a few numbers to get
      the feel of the editor. (At this stage numbers following a decimal
      point will not be displayed.) When you've filled a few rows and
      columns press the escape key (marked "Esc") and you will leave the
      editor. The "Select function -" message will be displayed.

      8. Type BASICS C1 then press ENTER. You will be shown the mean,
      variance, etc. of the numbers you typed into the first column.

      9. Type REGRESS C1 C2 then press ENTER. You will see the correlation
      coefficient and linear regression line for the first two columns.

      10. Type QUIT then press ENTER.

      11. Type YES then press ENTER.

      12. Now read the rest of the manual.

      2.3  INSTALLATION

      Installing EASISTAT is very simple. You just need to copy the files
      supplied to wherever you want them and set up your CONFIG.SYS file
      to contain the lines FILES=10 and BUFFERS=20, and if you know how to
      do that already you can skip down to the section called "Running
      EASISTAT".

      2.3.1  Installing EASISTAT on a hard disk

      We will assume you wish to install EASISTAT into a subdirectory
      called STATS of your hard disk. We will assume that your hard disk
      drive is called C: and your floppy disk drive is called A:.

      Put the floppy disk supplied into drive A: and close the door on that
      drive.

      Enter each of the following lines just as they are printed (by
      "enter" we mean type the line and then press the ENTER or RETURN
      key).

      C:
      MKDIR \STATS
      CHDIR \STATS
      COPY A:*.*


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                               EASISTAT.DOC

      The eight files that were on the floppy disk are now copied onto the
      hard disk into the subdirectory called STATS. Put the floppy disk
      away somewhere safe.


      2.3.2  Installing EASISTAT on a floppy disk

      We will assume that you have a floppy disk drive called A:. If you
      have a second floppy disk drive it will be called B:, otherwise your
      computer will pretend that your one drive is actually two and will
      keep asking you to swap disks.

      Put the floppy disk supplied into drive A: and close the door on that
      drive. If you have a second drive put a blank formatted disk into
      that drive and close the door. Otherwise just have the second disc
      ready to swap when the computer tells you to.

      Enter each of the following lines just as they are printed (by
      "enter" we mean type the line and then press the ENTER or RETURN
      key).

      A:
      COPY *.* B:

      (If you have only one drive the computer will ask you to swap the
      disks around, so just follow its instructions. The "disk for
      drive A:" is the one we have supplied and the "disk for drive B:"
      is the blank one to copy the program onto.)

      The eight files that were on the floppy disk supplied are now
      copied onto a working disk. Put the original disk away somewhere
      safe.

      2.3.3  Setting up CONFIG.SYS

      For EASISTAT to work properly you should have the following lines in
      your CONFIG.SYS file:

      FILES=10
      BUFFERS=20

      (The values can be higher than 10 and 20, but should not be lower. If
      you choose to have deeply-nested command files and also want to have
      other files open at the same time, then the value for FILES may need
      to be even higher than 10, but 10 should suffice for normal usage.)

      Where is CONFIG.SYS?

      The CONFIG.SYS file is on the root directory of the disk from which
      you boot up, ie the disk which your computer reads when you first
      turn it on. If you put a floppy disk in drive A: before turning the
      computer on it will be this disk. Please put it in the drive (do not
      use the original disk supplied with your computer, but a copy of
      it). If you have a hard disk and do not put a floppy disk in the

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                               EASISTAT.DOC

      drive then the computer will boot from the hard disk (which we will
      assume is called C:).

      Depending on which of these is the case enter either:

      A:
      CD\

      or:

      C:
      CD\

      You are now in the root directory of your boot disk.

      Do you have a CONFIG.SYS file and what is in it?

      You may not have a CONFIG.SYS file at all. To see a list of all
      the files in this directory enter:

      DIR /W

      If you do not see CONFIG   SYS in the list of files then you do not
      have a CONFIG.SYS file and should skip to the section called
      "Creating a CONFIG.SYS file".

      If you do have a CONFIG.SYS file then to see what is in it enter:

      TYPE CONFIG.SYS

      If it already has lines saying:

      FILES=10
      BUFFERS=20

      (or higher numbers) then you can skip this section and go down to
      "Running EASISTAT".

      If it has no lines referring to files or buffers then enter the
      following line exactly as it is shown:

      COPY CONFIG.SYS+CON CONFIG.SYS

      the following lines should appear:

      CONFIG.SYS
      CON

      Now again enter the following lines:

      FILES=10
      BUFFERS=20

      and after the second line press the F6 key. The following symbol

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                               EASISTAT.DOC

      should appear: ^Z. (If it does not, hold down the CONTROL key and
      press the Z key.) Press ENTER again and the following message should
      appear:

              1 File(s) copied

      Now enter:

      TYPE CONFIG.SYS

      again to confirm that the lines you added have appeared on the end of
      the file. Now you can go on to the section titled "Running
      EASISTAT".

      If your original CONFIG.SYS file does have lines to set the numbers
      of buffers and files but these numbers are smaller than those
      suggested, then you should edit the file by using either a word
      processor capable of dealing with ASCII text or by using EDLIN which
      should have been supplied with your computer and which is described
      in the DOS manual.

      Creating a CONFIG.SYS file

      If you do not yet have a CONFIG.SYS file on your boot disk then to
      create a new one enter the following lines exactly as they appear:

      COPY CON CONFIG.SYS
      FILES=10
      BUFFERS=20

      and after the third line press the F6 key. The following symbol
      should appear: ^Z. (If it does not, hold down the CONTROL key and
      press the Z key.) Press ENTER again and the following message should
      appear:

              1 File(s) copied

      Now enter:

      TYPE CONFIG.SYS

      and the last two lines should appear again, indicating that they are
      in the file called CONFIG.SYS.

      2.3.4  Running EASISTAT

      (If you have just altered your CONFIG.SYS file then you should reset
      your computer or turn it off and then on again so that the changes
      you have just made can take effect.)

      To run EASISTAT just type EASISTAT at the DOS prompt and press ENTER
      (or RETURN). This will only work if EASISTAT.EXE is in the current



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      working directory. If you get the message:

      Bad command or file name

      then it means that DOS cannot find the file called EASISTAT.EXE in
      the current directory and either you must move to the directory
      where EASISTAT.EXE is or you you must tell DOS where it can find
      EASISTAT.EXE by giving the full pathname for it.

      As an example, suppose that you are currently logged on to drive A
      (which means that the DOS prompt will say A>, A:\> or something
      similar) and that EASISTAT.EXE is on the hard disk, drive C, in a
      subdirectory called STATS. Then to run EASISTAT you could enter one
      of the following two sets of commands:

      C:
      CHDIR \STATS
      EASISTAT

      or:

      C:\STATS\EASISTAT

      If you are not sure whether or not you are in the subdirectory which
      contains EASISTAT.EXE then enter DIR and you will see a list of all
      files in that subdirectory. If you do not understand how the
      subdirectory structure works and how to manipulate files with DOS
      commands, then we strongly advise you to study the DOS manual and
      make yourself familiar with the following commands: DIR, MKDIR,
      CHDIR, COPY, DEL, REN. They are quite straightforward when you get
      the hang of them and your computer will be much more useful to you
      once you have understood them.


      2.3.5  Using subdirectories

      The program EASISTAT is loaded from a program file called
      EASISTAT.EXE. As well as this file EASISTAT can also use four other
      kinds of file: data files, output files, graph files and command
      files. You will need to decide where you want to keep these
      different files.

      The simplest solution is to have EASISTAT.EXE and the other files
      used all on the same disk and all in the same subdirectory. Then
      whenever you want to use EASISTAT you should first move into that
      subdirectory (using the first of the two methods described in the
      section above) and then all the files will automatically be in
      the right place.

                                    * * * * *





                                    12




                               EASISTAT.DOC

      Example 1. EASISTAT.EXE and data files both on a disk in drive A.
      Enter:

      A:
      EASISTAT

      Example 2. EASISTAT.EXE on a disk in drive A and data files on a
      disk in drive B.
      Enter:

      B:
      A:EASISTAT

                                    * * * * *

      If you know how to use the PATH command you may want to put
      EASISTAT.EXE on the search path. See your DOS manual for details.

      2.3.6  If you only have one disk drive

      If you have EASISTAT.EXE on one floppy disk and your data files
      on another, then you can use them both in the same disk drive as
      follows:

      1) Put the disk containing EASISTAT.EXE in the drive, close the
      door of the drive and enter:

      EASISTAT

      2) Put the first disk aside and replace it with the disk which
      you wish to use for data files etc. When you use EASISTAT it will
      read and write the files on this disk.

      2.3.7 Command line parameters

      These are instructions to the program typed in on the same line as
      you type EASISTAT and control the way that the program starts up.

      They are entered as follows:

                                    * * * * *

      2.4  SCREEN LAYOUT

      The EASISTAT screen consists of two windows, a bottom window
      where you type in instructions for the program and a top window
      where the output from EASISTAT appears. The only exception to
      this is when you are using the editor, when you are allowed to
      type directly into the top window.

      It is important to keep this distinction clearly in mind because
      when you learn how to use command files and output files you will
      find that command files consist of exactly what you type into the
      bottom window, and output files consist of exactly what comes out

                                    13




                               EASISTAT.DOC

      of the top window.

      Sometimes the output from EASISTAT is too wide to all fit on the
      screen (for example when listing rows of data). When this happens
      only part of the output will be viewed on screen, but if an
      output file is open then all the output will be sent to that.

      2.5  KEYBOARD INPUT

      Every time the "Select function -" message appears you can type
      normal letters, numbers and punctuation along a line and can use
      the BACKSPACE key to correct mistakes. When you have finished
      typing what you want press the ENTER key and EASISTAT will act on
      what you have typed. This will be described as entering a line.
      On some computers the ENTER key is called RETURN or CR or is marked
      with an arrow going down and then left. For brevity we will just
      refer to it as the ENTER key. Please note that anything you type can
      use either capital letters or lower case letters, or if you like a
      mixture of the two. We have used capital letters a lot in this
      manual to try to make things clear, but there is no need at all for
      you to use them if you find lower case letters more convenient.

      When using the special data editor called up by the EDIT command
      you will need to use the special keys on the numeric keypad, the
      ESCAPE key and the CONTROL key. The special keys comprise the
      cursor keys and the HOME, END, PAGEUP, PAGEDOWN and DELETE keys.
      The cursor keys are referred to as RIGHT ARROW, DOWN ARROW etc.
      If you do not have these keys in a special cluster then make sure
      to turn off the NUMLOCK key before using them. The ESCAPE key is
      marked "Esc" and is usually up to the top left of the keyboard. To
      use the CONTROL key (the key marked "Ctrl" near the bottom left of
      the keyboard) first hold it down and then while keeping it pressed
      push the key that goes with it, so to type CONTROL-F hold down the
      CONTROL key, press and release the F key, and finally release the
      CONTROL key.

      2.6  DESCRIPTION OF FILES USED BY EASISTAT

      EASISTAT reads and writes four kinds of files. These are data
      files, output files, graph files and command files. Command files
      are sometimes also referred to as input files.

      2.6.1  Data files

      Data can be stored in these files by EASISTAT, and EASISTAT can
      read data files either that it has written itself or that have
      been produced by another program like a spreadsheet or
      wordprocessor. The command used to read a data file is DATA, and
      to save a data file DATA SAVE is used. Please see the section on
      the DATA command for details of the format of data files.

      2.6.2  Output files

      These are files containing the results of EASISTAT's statistical

                                    14




                               EASISTAT.DOC

      tests, or anything else which you ask the program to write out.
      They contain copies of all the output which appears in the top
      window of the screen. They are created with the OUTPUT command,
      so please see the section on this command for details.

      2.6.3  Command files

      These contain lists of commands for EASISTAT to perform, just as
      if you were typing in those commands at the keyboard. They are
      read using the INPUT command and can be written using a word
      processor or the LOG command. Please see the sections on these two
      commands for details. Command files are a powerful facility of
      EASISTAT allowing you to run long statistical analyses automatically
      from a series of commands that you have prepared in advance, and
      also make it possible to run EASISTAT from within DOS batch files.

      2.6.4 Graph files

      Although EASISTAT cannot draw graphs itself, it can output
      information which allows other programs to draw graphs from
      EASISTAT's data. These graph files are produced by the CHISQ
      command using the G option.

      2.7  EDITING FILES

      The four kinds of auxiliary file EASISTAT uses, data, output,
      graph and command files, are all ASCII files. This means that they
      are files containing only normal characters like letters, numbers,
      punctuation and line feeds, and none of the special characters
      that some word processors use. Although it is not absolutely
      essential to do so, it will add enormously to the value and
      convenience of EASISTAT if you have the ability to edit these
      files, and to do that you need a word processor or editor that
      can deal with ASCII text. Most word processors nowadays do have
      an option to do this (in fact if yours does not we suggest you
      might think about getting a new one) however sometimes it can be
      difficult to tell from the manual how to select this option.

      Your word processor may work with ASCII files as a matter of
      course. To test this, run your word processor and type a few
      lines of text then save it in a file called TEST and quit the
      word processor. Now type TYPE TEST or COPY TEST CON. In each case
      what you typed should appear on the screen, and if it appears
      just as you typed it with no funny smiley faces or weird symbols
      or beeps then it is an ASCII file and you can use your word
      processor to edit EASISTAT files directly. An example of a word
      processor that uses ASCII files is PC-Write.

      If (as is more likely) you do get a few funny symbols then you
      are going to have to find out if there is a special option to
      read and write ASCII files. Try looking for one of the following
      options in your word processor manual: ASCII, Import/Export text,
      Save/Retrieve DOS text, non-document mode. If you find something
      that looks likely then use it to save a file to disc and then use

                                    15




                               EASISTAT.DOC

      the TYPE command to display it as suggested above.

      If you can't find any way for your word processor to handle ASCII
      then you will have to use something else to edit files with
      (though it is not impossible to use EASISTAT without the
      auxiliary files, just inconvenient). You could use EDLIN, which
      is a program supplied free with most computers and is described
      in your DOS manual, but it is not very powerful or user friendly.
      Instead we would recommend that you spend a few pounds to acquire
      a copy of PC-Write from a firm which distributes ShareWare (see the
      section above on "Other Shareware programs").

      2.8  DRAWING GRAPHS

      It is planned to produce a program called EASIPLOT which will
      produce graphs from EASISTAT'S graph files, but this is not yet
      available. However the graphs can be displayed using a program called
      PCG2 which is distributed with a Shareware database called
      PC-File:dB. This is a well worth acquiring in its own right anyway.
      For details of where to obtain a copy see the section above on
      "Other Shareware programs".


































                                    16




                               EASISTAT.DOC

      Chapter 3               COMMAND SYNTAX

      EASISTAT stores its data in a table of values arranged in rows and
      columns. To get EASISTAT to do anything you have to give it a
      command, or function, to perform. Most commands will also require
      other information, such as which columns to apply a particular
      analysis to. The way in which this information is specified can be
      called the format or syntax of the command. When each command is
      described in this manual its format is defined with it, but to
      understand the format required there are some important general
      rules it is helpful to become familiar with first.

      To illustrate these rules we will take the BASICS command, which
      is described later in the manual in the following way:

      Format: B[asics] [ranks] column [if condition]

      This means that the function is called BASICS, but that all but
      the first letter B is optional, that it can have an optional
      switch called RANKS, that the column to be studied must be
      specified, and that finally one can add logical and arithmetic
      conditions limiting the rows to be studied by entering IF
      followed by a condition. This means that one can enter for
      instance:

      BASICS RANKS C1 IF (C2-C3)<7

      This command would cause the basic description of the values in
      column 1 to be displayed (their mean, mode, standard deviation,
      etc.). Only certain rows would be used - those for which the value
      in column 3 subtracted from the value column 2 was less than 7. It
      would also display the rank and frequency table of the values. In
      the sections which follow we will look at the individual aspects of
      command format more closely.





















                                    17




                               EASISTAT.DOC

      3.1  SELECTING A FUNCTION

      Here is the list of functions available (it is displayed by
      EASISTAT when the HELP command is selected):

      Help                                Titles
      Basics [ranks] column [if cond]     Data [save] [filename]
      List [if cond]                      Chisq [Fish] [Num] [Yates] [Graph]
      Wilcoxon [column]                   Ttest [paired]
      Anova [column]                      Kendall's [column column]
      Kolmogorov [column]                 Regress [column column]
      Multiple regression [column]        Component analysis
      Narrow cond                         Widen [cond]
      Arithmetic                          New [column or row or next]
      Label [column [name]]               Format [col or default [width dec]]
      Derive [column [sum]]               Delete [column or row]
      Echo                                Input [filename or close]
      Output [filename or close]          Log [filename or close]
      Edit                                Screen
      Sort [down] [column]                Pause
      System [command]                    Quit

      To select one of these functions when asked simply type in the
      first word of the name of the function. You do not have to type
      in the whole word. EASISTAT will select the first function from
      the above list that matches the letters you have typed. So to
      select the BASICS function you could type:

      BASICS
       or:
      BAS
       or:
      B

      Note that if you type:

      W

      you will get the WILCOXON function and not the WIDEN command. If
      you want the WIDEN command you would have to type at least:

      WID

      Remember eveything can be typed in upper or lower case, or a
      mixture. So:

      b

      is just as good as:

      BASICS




                                    18




                               EASISTAT.DOC

      To use the same example given above, one could type:

      B RANKS C1 IF (C2-C3)<7

      or:

      bas ranks c1 if (c2-c3)<7

      and achieve just the same result.

      When the format of a command is described in this manual, square
      brackets are put round the optional letters of the command name,
      eg:

      B[asics]
      Wid[en]

      3.2  COMMAND OPTIONS

      Some of the functions can have different options attached to
      them. An option appears in square brackets in the list above and
      when the manual describes each function. An option can be
      selected or not, and sometimes more than one option can be
      selected. BASICS has an option, RANKS, which makes it print out a
      list of values in rank order together with values for percentage
      and cumulative percentage. An option is specified by the first
      letter, although the whole word can be typed for clarity. Taking
      the above example one could enter:

      BASICS RANKS C1 IF (C2-C3)<7

      or:

      b r c1 if (c2-c3)<7

      If the r is left out, the BASICS function will do exactly the
      same thing but without also producing the rank/frequency table:

      b c1 if (c2-c3)<7

      The second option available in BASICS is IF followed by a
      condition which specifies wich rows to study. IF is exceptional
      in that it must be written in full, just I would not be adequate.
      This option similarly can be left out, in which case all the rows
      will be included in the analysis:

      b c1

      or:

      BASICS C1

      For some of the other functions (though not BASICS), a column or
      filename is shown as being optional by being put in square brackets.

                                    19




                               EASISTAT.DOC

      This means that you do not have to type the column in the command
      line, but then you will be asked by EASISTAT to specify which column
      you mean in a second line. It's just a question of convenience for
      you whether you put the column into the command line or not. When
      you first start to use EASISTAT it is better just to select a
      function and then EASISTAT will ask you for other details, but as
      you grow more familiar with the program you may feel like typing
      more into the first line. There is an important point however.
      Although if you omit a necessary parameter like a column number you
      will usually be asked to supply it, in contrast if you omit an
      option like RANKS or IF from the command line you cannot add it in
      later in a second line. All the command options must be specified in
      the command line.

      3.3  REFERRING TO ROWS AND COLUMNS

      EASISTAT is based around the concept that all the different
      variables attached to one data object (eg an experimental
      subject) are in one row, and that they are arranged in columns
      according to the quantity they measure. So one column might be
      for temperature, another for mass, etc. and one row might be for
      one rock and another row for another. Thus the statistical
      functions essentially operate on columns - the mean of one rock's
      weight and temperature would make little sense.

      In almost all functions we need to be able to tell EASISTAT which
      columns we want to look at and to do this we type C followed
      immediately (no space) by a number between 1 and the number of
      columns there are, eg C1, c3 or c25. Occasionally we may wish to
      refer to a specific row - when we want to delete a certain row
      perhaps. To do this we type the keyword ROW followed by a space
      and then the number of the row we mean, eg row 4 or ROW 29. There is
      really nothing much that EASISTAT can do with rows except insert
      them or delete them. We used this syntax in the example above
      when we said :

      b c1

      meaning take the basic statistics of all the values appearing in
      the first column.

      In the logical and arithmetic expressions described below it is
      necessary to refer to the values which appear in cells in
      different rows. The rows are looked at one at a time and then the
      value specified is taken from that row, so that in a logical
      function c15 means "the value appearing in column 15 of the row I
      am currently interested in". In this context the keyword ROW
      (here appearing with no number after it) means "the number of the
      row I am currently interested in". In fact, we don't think you'll
      be referring to row numbers much and the whole thing should become
      fairly clear with a few examples.




                                    20




                               EASISTAT.DOC

      3.4  LOGICAL EXPRESSIONS

      In the example above there is a condition which specifies which
      rows are to be included in the analysis, and in general a
      condition is a statement of a logical function which is either
      true or false. So c5>6 is true if the value in the fifth column
      of a given row is 9, but false if it is 2. Conditions are used to
      specify whether or not a row belongs to a given group, and in the
      example given whether or not it should be included with the other
      values towards deciding the sample mean, standard deviation, etc.

      b c1 if (c2-c3)<7

      means that if the statement given is true for a particular row
      then the value in column one will be taken and added to the
      sample and incorporated in the measurement of mean and standard
      deviation, but if not that particular row will be ignored for the
      purpose of the current analysis and left out of the sample.

      Here is a list of all the logical operators:

        x | y     x OR y                   (either can be true)
        x & y     x AND y                  (both must be true)
        x != y    x NOT EQUAL TO y
        x = y     x EQUAL TO y
        x < y     x LESS THAN y
        x > y     x GREATER THAN y
        x <= y    x LESS THAN OR EQUAL TO y
        x >= y    x GREATER THAN OR EQUAL TO y
        ! x       NOT x

      (The | symbol meaning OR appears as a broken vertical bar on the
      screen and as either a solid or broken bar on the keyboard, often
      above the backslash symbol: \.)

      The expression is true if the relationship between x and y is as
      described, but false if not. The OR relationship is true if
      either condition x or condition y is true, and the AND
      relationship is true only if both condition x and condition y are
      true. Here are some examples:

      c13>c12
      - the value in column 13 must be higher than the value in column
      12

      c13<=c12
      - the value in column 13 must be less than or equal to the value
      in column 12, ie it must not be greater than it

      !(c13>c12)
      - the value in column 13 must not be greater than the value in
      column 12, ie the same effect as the previous example



                                    21




                               EASISTAT.DOC

      c5>5
      - the value in column 5 must be greater than 5

      (c5>5)|(c6<10)
      - either the value in column 5 must be greater than 5 or the
      value in column 6 must be less than 10 for the condition to be
      true

      (c5>5)&(c6<10)
      - both the value in column 5 must be greater than 5 and the value
      in column 6 must be less than 10 for the condition to be true

      (c5>5)&(c5<10)
      - the value in column 5 must both be greater than 5 and less than
      10, ie the value in column 5 must lie between 5 and 10

      (c5=3)|(c5=5)|(c5=7)
      - the value in column 5 must be 3, 5 or 7

      (c5=3)&(c5=5)&(c5=7)
      - this can never be true, the value in column 5 cannot be 3 and 5
      and 7 all at once

      (c5!=3)&(c5!=5)&(c5!=7)
      - the value in column 5 must be anything except 3, 5 or 7

      (c5=2.2) | (((c5>5) & (c5<10)) & !((c5>6) & (c5<7)))
      - the value in column 5 can be 2.2, or else it must lie between 5
      and 10 but must not lie between 6 and 7

      So you see expressions can be made as simple or as complicated as
      you like, and sub-clauses are contained in brackets. In fact the
      brackets are not always necessary - see the section below on
      operator precedence. Spaces occurring in logical and arithmetic
      expressions are ignored.

      When the keyword ROW is used in a condition then the number of
      the row itself is tested, so:

      row<5

      is true if the number of the row is less than 5, ie one of the
      first four rows.

      Contrast this to:

      c1<5

      which as we have already discussed means the rows for which the
      value in the first column is less than 5.

      There is no reason why references to rows and column cannot be



                                    22




                               EASISTAT.DOC

      combined in the same expression, eg:

      (c1<10) & (row<5)

      or even:

      c1<row

      Note to users familiar with spreadsheets:

                                    * * * * *

      3.5  ARITHMETIC EXPRESSIONS

      When we said C2-C3 in the first example, that was an arithemetic
      expression meaning (obviously) the value in column 3 subtracted
      from the value in column 2. Many other functions are available,
      and here is a complete list:

      x - y     x MINUS y
      x + y     x PLUS y
      x mod y   x MODULO y
      x / y     x DIVIDED BY y
      x * y     x TIMES y
      x pow y   x TO THE yTH POWER
      x pX y    PROBABILITY OF CHI-SQUARED x WITH y DEGREES OF FREEDOM
      x pT y    PROBABILITY OF STUDENT'S T x WITH y DEGREES OF FREEDOM

      abs x     ABSOLUTE VALUE OF x
      log x     LOG x BASE 10
      ln x      NATURAL LOG OF x                              (base e)
      exp x     e TO THE xTH POWER                   (natural antilog)
      sin x     SIN x RADIANS
      arcsin x  ARCSIN x
      cos x     COS x RADIANS
      arccos x  ARCCOS x
      tan x     TAN x RADIANS
      arctan x  ARCTAN x
      pN x      ONE-TAILED PROBABILITY OF x IN A NORMAL DISTRIBUTION
      lfact x   NATURAL LOG OF FACTORIAL x

      Arithmetic expressions can be written out just as they appear on
      paper, again with brackets to clarify the order of operations
      (please see the section on operator precedence to see the
      importance of using brackets correctly, it's not what you might
      think):

      c3+c4*6
      (c3+c4)*6
      (c4*c5)pow3

                                    * * * * *



                                    23




                               EASISTAT.DOC

      c13 pX 3

      This example would take the value in column 13 to be a chi-squared
      statistic with three degrees of freedom and computes its
      probability, or p value. See the section on the ARITHMETIC function
      for details of how to use EASISTAT as a set of statistics tables to
      look up.

      3.6  OPERATOR PRECEDENCE

      Operator precedence means the order in which logical or arithmetic
      operation are performed. We are all familiar with the idea that:

      3+4/2

      means three added to four-divided-by-two and not three-plus-four
      divided by two, so that the answer is 5 and not 3.5. However in
      EASISTAT things are taken a little bit further (this is not a
      feature, it is a bug) in that some operations are always performed
      before others, even though they shouldn't be. In particular addition
      is always performed before subtraction so that:

      9-3+1 = 5

      because it is taken to be:

      9-(3+1)

      Similarly multiplication is always performed before division.
      Here is a complete list of precedences:

        x | y
        x & y
        x != y
        x = y
        x < y
        x > y
        x <= y
        x >= y
        x - y
        x + y
        x mod y
        x / y
        x * y
        x pow y
        x pX y
        x pT y

      The lower down an operator is, the sooner it is performed, as if it
      was enclosed in a pair of brackets. This means that writing:

      c1+c2*c3+c4powc5*c6/4pt15



                                    24




                               EASISTAT.DOC

      is equivalent to writing:

      c1 + (c2*c3) + (((c4powc5)*c6) / (4pt15))

      If you want the operations carried out in any other order then you
      have to explicitly specify it yourself using brackets.

                                    * * * * *

      3.7  COMBINING ARITHMETIC AND LOGICAL FUNCTIONS

      Not only can arithmetic and logical operations be arbitrarily
      complex, they can also be combined together in very flexible
      ways. Of course we have already seen examples of this because
      (c2-c3)>7 combines an arithmetic expression, c2-c3, with a
      logical one, sum>7.

                                    * * * * *





































                                    25




                               EASISTAT.DOC

      Chapter  4            DATA MANAGEMENT FUNCTIONS

      In this chapter we describe how to manipulate the data which
      EASISTAT uses. For details on how to read and write data files on
      disk see the section on file management functions and the DATA
      command.

      4.1  EDIT


      Format: Ed[it]

      EDIT is the command used to invoke EASISTAT's special data editor.
      The editor displays the data values in a table of rows and columns.
      Using the cursor keys you can move freely over this table and
      inspect, change or add values at will.

      Special keys are used to operate the editor in a way which does
      not apply to the rest of EASISTAT's functions. It is not possible
      to operate the editor from a command file (though it can be
      invoked from a command file) - the editor can only be operated
      directly from the keyboard.

      Examples:

      Select function -  edit
      Select function -  ED
      Select function -  ed

      All the above commands will invoke the editor.

      Movement keys

      RIGHT ARROW              - move one cell right
      LEFT ARROW               - move one cell left
      UP ARROW                 - move one cell up
      DOWN ARROW               - move one cell down

                                    * * * * *

      Keys to add new rows and columns

      ENTER                    - move down a row and go to first column
                                 of it, and if on last row create a
                                 new row below it
      CONTROL-RIGHT ARROW      - if on last column, create a new column
                                 to the right

                                    * * * * *

      Keys to change column format

                                    * * * * *


                                    26




                               EASISTAT.DOC

      Special keys

      DELETE                   - deletes the contents of a cell
      BACKSPACE                - deletes last letter typed
      ESCAPE                   - finishes editing, returns to main
                                 program

                                    * * * * *


      So to enter your data using the editor proceed as follows:

      1) When asked to "Select function - " enter ED.

      2) Move the cursor to the titles row, which if the table is empty
      will say NEW.

      3) Type in the title which you want,

                                    * * * * *

      4) Press CONTROL-RIGHT ARROW to make a new column to the right.

      5) Keep repeating steps 3 and 4 until you have enough columns.
      (Note that every column must have a title, you cannot leave the
      title blank.)

      6) Press ENTER to go to start of the next row of values.

      7) Enter the correct value in a cell.

      8) Press RIGHT ARROW to move to the next column.

      9) Keep repeating steps 7 and 8 until you have filled the row.

      10) Keep repeating steps 6, 7, 8 and 9 until you have entered all
      the data.

      11) Press ESCAPE.

      12) Use the DATA SAVE command to save your data to disk (eg enter
      DATA SAVE MYDATA.DAT, see the section on the DATA command for
      details).

      Note the following points:

      If you make a mistake just go back to the cell and type in the
      correct value.

                                    * * * * *





                                    27




                               EASISTAT.DOC

      4.2  TITLES

      Format: T[itles]

      This command outputs a list of the titles of the columns of the
      current data set. This is helpful to remind you what the column
      numbers refer to.

      Examples:

      Select function -  t
      Select function -  TITLE
      Select function -  Ti

      All these commands will have the same effect.

      Example output:

                                    * * * * *

      Comments

                                    * * * * *

      4.3  LIST

      Format: L[ist] [if condition]

      This function lists all the rows of data, or can be followed by
      an optional condition to list only some of the rows.

      Examples:

      Select function -  l

      Select function -  LI

      These will have the same effect of listing out all the rows.

      Select function -  l if c1<5

      This will only list out those rows in which the first value is
      less than 5.

      Select function -  LIST IF ROW<=5

      This will only list out the first 5 rows.

      Example output:

                                    * * * * *

      Columns are listed according to the format currently assigned to
      that column in terms of column width and number of decimal places

                                    28




                               EASISTAT.DOC

      displayed. You can alter these with the FORMAT command.

      Comments

                                    * * * * *

      4.4  NEW

      Format: Ne[w] [column] or [row [number]]

      Inserts a new column or row in the data table. The new column
      will be given the title NEW and will have the default width and
      number of decimal places displayed. If instead of a numbered
      column the key word NEXT is used then a new column will be
      created to the right of the table. If instead of a number after
      the keyword ROW the keyword NEXT is given then a new row will be
      added to the bottom of the table. The new column or row is filled
      with zeroes.

      Examples:

      Select function -  new c2

      Creates a new column in the second position.

      Select function -  new row 4

      Creates a new row in the fourth position.

                                    * * * * *

     4.5  DELETE

      Format: Del[ete] [column] or [row [number]]

      Deletes a row or column. All the other rows or columns are moved
      up or to the left one space to fill the gap.

      Examples:

      Select function -  delete c2

      Deletes second column.

      Select function -  DEL ROW 4

      Deletes fourth row.

                                    * * * * *
      4.6  LABEL

      Format: La[bel] [column [new name]]

      This is the command used to change the title appearing at the top

                                    29




                               EASISTAT.DOC

      of a column.

      Examples:

      Select function -  lab c2 logA

      Now the new title for c2 is logA.

                                    * * * * *

      4.7  FORMAT

      Format: F[ormat] [column or default [width decimals]]

      The FORMAT command allows changes in the way a column is
      displayed by EDIT, LIST and when the DATA SAVE command is used.
      The column width and number of decimal places displayed can be
      changed. If instead of a column the keyword DEFAULT is used, then
      all new columns will be created according to the specification
      given.

      Examples:

      Select function -  f c2 6 3

      This changes the format of the second column so that it is six
      digits wide and three decimal places be displayed after the
      decimal point, eg numbers will be shown as 23.319, 6.000.

                                    * * * * *

      Comments

      It is vital to realise that when you save data to disk you are
      only saving the values to the precision of the current column
      format. All the time EASISTAT holds data in its memory it treats
      values as floating point numbers which are stored with a high
      precision. As soon as they are saved to disk however they are
      treated as digits as you see them displayed, so that if a
      fractional number is displayed with no decimal places then it
      will be saved as a whole number and the fractional part will be
      lost.

                                    * * * * *

      4.8  DERIVE

      Format: Der[ive] [column [sum]]

      This is a very powerful function which allows you to transform
      values in one column or to derive the values in one column from the
      values in others. One column can be set to be for example the total
      of three others, the maximum, the product, or can be produced by any
      arbitrarily complex arithmetic and logical expression. In addition

                                    30




                               EASISTAT.DOC

      two special options are provided to make one column the rank of the
      values in another, or to be the normalised version of those values
      ie with the column mean subtracted and divided by the column
      standard deviation. When the column width is too small for the new
      derived value it is adjusted automatically.

      In the format set out above "sum" can be an arithmetic expression
      like (c3+c4)/2 or it can be one of these two special functions of
      a column, ZED or RANK.

      ZED column                - (column - mean)/standard deviation
      RANK column               - rank of values in given column

      Examples:

      Select function -  der c3 c4-c5

      This sets the values in column 3 to be those in column 5 minus
      those in column 4.

      Select function -  DERIVE
      Enter column to derive:   c3
      Enter formula for new values:   c4+c5

      If you don't supply the column and expression on the command line
      then EASISTAT will ask for them. Here is third column becomes the
      sum of the fourth and fifth.

      Select function -  der c6 zed c5

      Values in column 5 have the column mean subtracted and are then
      divided by the standard deviation so that the values in column 6
      will now have mean of zero and standard deviation of one.

      Select function -  der c6 rank c5

      Now the values in column 6 are derived from the ranks of those in
      column 5, so that the row containing the lowest value in column 5
      will have a 1 in column 6, the next lowest a 2, and so on.

      Advanced tips

                                    * * * * *

      4.9  SORT

      Format: So[rt] [down] [column]

      The SORT command arranges all the rows in order according to the
      values in the column specified. If the keyword DOWN is given they
      are arranged in descending order, otherwise ascending.




                                    31




                               EASISTAT.DOC

      Examples:

      Select function - SORT C3

      Select function - s d c15

      Example output:

                                    * * * * *

      Comments:

                                    * * * * *

      4.10 NARROW

      Format: N[arrow] condition

      The NARROW command narrows down the data set to include only
      those rows for which the given condition applies. All operations
      will subsequently only apply to the reduced data set except the
      following: EDIT, TITLES, NEW, DELETE, FORMAT, SORT. The data set
      remains narrowed until a WIDEN command is issued.

      Examples:

      Select function -  NARROW C3=1

      Only the rows whose first value is 1.

      Select function -  n row<50

      The first 49 rows.

      Select function -  n c3!=9 & c4!=9

      The rows which do not have a 9 in either the third or fourth
      column.

      Example output:

                                    * * * * *

      Comments

                                    * * * * *

      4.11  WIDEN

      Format: Wid[en] [condition]

      The WIDEN command restores the data set after a NARROW command.
      If no condition is given then all the the rows are included. If a
      condition is given, then all the rows previously included will

                                    32




                               EASISTAT.DOC

      remain, but any others that comply with the condition will be
      included in addition.

      Examples:

      Select function -  WIDEN

      Includes all rows.

      Select function -  wid c3=4

      Adds in rows for which third entry is 4.

                                    * * * * *

      Example output:

                                    * * * * *

      Comment

                                    * * * * *

































                                    33




                               EASISTAT.DOC

      Chapter 5              STATISTICAL FUNCTIONS

      In this chapter the statistical functions available are described.
      This manual does not seek to replace a statistics textbook, so only
      minimal guidance will be given as to which tests are appropriate for
      which data. The field is complex and controversial and if the user
      is not sure which test to use he should consult a textbook or
      professional statistician for guidance.

                                    * * * * *

      5.1  BASICS


      Format: B[asics] [ranks] column [if condition]

      Outputs basic information about the data in a column - the total
      of the values in the column and the number of items, and the mean
      mode, median, minimum, maximum, variance, standard deviation and
      standard error of the mean. Optionally a frequency and rank table
      of the values may also be produced.

      Select function -  BASICS C15

      Select function -  BAS C15 IF ROW<=50

      Select function -  b ranks c19

      Example output:

                                    * * * * *

      Comments

                                    * * * * *

      The standard deviation given is the actual standard deviation of
      the sample, ie the square root of the sum of the squares of the
      difference between each value and the mean divided by the number of
      items. The estimated standard deviation of the population is
      obtained by dividing the same sum by the number of items minus one.
      It is almost always the latter figure which should be quoted as "the
      standard deviation". It represents an attempt to estimate the
      standard deviation of the measure in the whole population from which
      the sample was drawn, and seeks to correct for the effects of the
      limited sample size. Equivalent remarks apply to the values quoted
      for variance and estimated population variance - generally the
      latter should be used.

                                    * * * * *





                                    34




                               EASISTAT.DOC

      5.2  CHI-SQUARED

      Format: C[hisq] [F] [Y] [N] [G]
                    - F means always do Fisher's exact test
                    - Y means apply Yates' correction
                    - N means enter numbers by hand, not from data
                    - G means produce a graph file and display graph

      This command sets up a contingency table and performs a
      chi-squared test on that table to determine the extent to which
      the values in the table depart from the expected.

      There are four options. An F will mean that provided a
      two-by-two table is used Fisher's exact test will always be
      performed, regardless of the values in the table. EASISTAT
      automatically performs Fisher's exact test if there is a total of
      less than 20 items in the table or if the expected value for any
      cell is less than 5, but specifying F will cause EASISTAT to
      perform Fisher's test even if these conditions are not met.
      Specifying Y applies Yates' correction when calculating the
      differences between observed and expected values. The N option
      means that instead of composing the contingency table from the
      data in EASISTAT's data set, the user can enter by hand the
      values that he wants to appear in each cell of the table. The G
      option causes a graph file to be written to disk and, provided PCG2
      is available, displayed. Any, all, or none of the options may be
      used at once.

      Example:

      Select function -  CHISQ

      - Chi-squared test -
      Input number of columns:    2
      Input number of rows:    2
      Enter condition for column 1: C15<12
      Enter condition for column 2: C15>=12
      Enter condition for row A: C3=1
      Enter condition for row B: C3=2

      Output:

                                    * * * * *


      Comments

                                    * * * * *

      Drawing graphs

      Specifying the G option causes EASISTAT to write a file called
      GRAPH.ME to disk, and then to run a program called PCG2 to display
      graphs of the data. PCG2 is provided with another Shareware program

                                    35




                               EASISTAT.DOC

      called PC-File:dB - see the section on "Other Shareware programs".

                                    * * * * *

      5.3  WILCOXON'S RANK SUM

      Format: W[ilcoxon] [column]

      This function performs Wilcoxon's rank sum test (equivalent to
      Mann-Whitney and Kendall's S), to compare a nonparametric measure
      between two groups.

      Example:

      Select function -  w c15
      Enter condition for first group:   c3=1
      Enter condition for second group:   c3=2

      Output:

                                    * * * * *

      The rank sum is taken as an approximation to a normal distribution
      with mean and standard deviation derived as described by Berry and
      Armitage. The probability value given is the one-tailed probability
      of a difference between the groups of such magnitude in the given
      direction appearing by chance. For low numbers in each group (less
      than about twenty) the user may prefer to refer to a set of tables
      quoting the exact probability value for the rank sum dependent on
      the numbers in each group.

      5.4  KENDALL'S RANK CORRELATION COEFFICIENT

      Format: K[endall] [column column]

      Compares two columns of nonparametric data using Kendall's rank
      correlation coefficient.

      Examples:

      Select function -  KEND C15 C16

                                    * * * * *

      The correlation coefficient is sometimes referred to as Kendall's
      tau. Kendall's S is taken as an approximation to a normal
      distribution with mean and standard deviation derived as described
      by Berry and Armitage. The probability value given is the one-tailed
      probability of Kendall's S of such magnitude assuming this normal
      distribution. It is the one-tailed probability that a correlation of
      such magnitude in the direction given could have occurred by chance.




                                    36




                               EASISTAT.DOC

      5.5  KOLMOGOROV-SMIRNOV TEST

      Format: Ko[lmogorov] [column]

      This compares a nonparametric measure between two groups and tests
      whether the distribution of values between them is significantly
      different.

      Examples:

      Select function -  ko c15
      Enter condition for first group:   c3=1
      Enter condition for second group:   c3=2

      Select function -  ko
      Enter column to test:  c15
      Enter condition for first group:   c5<4
      Enter condition for second group:   c5>=4

      If the column supplying the variable is not included in the first
      line EASISTAT will ask for it.

      Output:

      Kolmogorov-Smirnov comparison of two groups using C15 (GHQ)
      C5<4
      C5>=4
      K-S statistic = 0.4302
      p = 0.0002

      Comments

      This test is not described in Berry and Armitage, but it is
      sometimes used and it should not be hard to find a reference to it
      in a statistics textbook (our implementation is from Numerical
      Recipes in C by Press et al). The function of this test is similar
      to Wilcoxon's rank sum test, except that it does not test whether the
      values in one group are in general higher or lower than those in the
      other, but only whether the distributions differ. It might therefore
      be possible to detect that two distributions with equal means or
      medians were significantly different because of differences in
      skewness or kurtosis.

      5.6  T TEST

      Format: Tt[est] [P [column column]]
          or: Tt[est] [column]

      Performs paired or unpaired Student's T to compare a parametric
      measure in two groups. For the unpaired test the values all lie
      in one column (as for the Wilcoxon test). For the paired test two
      columns are compared, the measures in each row taken to be
      paired.


                                    37




                               EASISTAT.DOC

      Example:

      Select function -  tt
      Enter column to test:    c15
      Enter condition for first group:  c3=1
      Enter condition for second group:  c3=2

      Output:

                                    * * * * *

      Two tests are performed. One assumes that although the means may
      differ between the groups, the variances do not. This compares
      the means of the groups according to a t statistic and outputs a
      two-tailed probability value for the difference between the two
      means to be as large as it is by chance. The second test does not
      make the assumption of equal variances. It takes the difference
      between the means to approximate a normal distribution and quotes
      the two-tailed probability for the difference to be as large as
      it is. This latter test is more controversial.

      Example:

      Select function - TTEST P C16 C17

      (where the P stands for paired)

      Output:

                                    * * * * *

      Each row contains a pair of values, one in each of the columns
      specified. The mean of the difference between these values is
      taken to be a t statistic and the probability value quoted is the
      two-tailed value for a difference as large as this to occur by
      chance.

      5.7  LINEAR REGRESSION AND CORRELATION COEFFICIENT

      Format: R[egress] [column column]

      Calculates the correlation coefficient (sometimes called Pearson's
      correlation coefficient) between two parametric measures in different
      columns, and calculates the linear regression line ("least squares
      fit") for the second column on the first.

      Examples:

      Select function -  REG C15 C16

      Select function -  r
      Enter two columns to compare (one on each line):
      c15
      c16

                                    38




                               EASISTAT.DOC


      Output:

                                    * * * * *

      The correlation coefficient, r, is output. The standard error of
      the gradient of the line SE(b) is output, and this can be taken
      to be distributed as a t statistic allowing the calculation of
      confidence limits. It is also used to calculate the significance
      of the results - the probability value quoted is a two-tailed
      value for a correlation of such magnitude to occur by chance.

      5.8  ANOVA

      Format: A[nova] [column]

      One-way analysis of variance of a parametric measure between
      groups.

                                    * * * * *

      Example:

      Select function - A

      - One-way analysis of variance -
      Enter column for dependent variable
      c15
      Input number of groups:   4
      Enter condition for group A:    c5=1
      Enter condition for group B:    c5=2
      Enter condition for group C:    c5=3
      Enter condition for group D:    c5>3

      Output:

                                    * * * * *

      The analysis of variance outputs an overall significance
      representing the probability that all the group means could have
      varied so much by chance. It is a two-tailed test. It also
      computes a t statistic and two-tailed probability value for the
      difference between the means for each pair of groups. This latter
      differs from performing an ordinary unpaired t test between the
      two groups only in that the whole sample is used to provide an
      estimate of the overall variance of the measure, rather than just
      relying on the values in the pair of groups under consideration.

      5.9  MULTIPLE REGRESSION

      Format: M[ultiple] [column]

      Performs multiple linear regression with several independent
      variables and one dependent variable.

                                    39




                               EASISTAT.DOC


                                    * * * * *

      Example:

      Select function - m

      - Multiple linear regression -
      Enter column for dependent variable
      c27
      Input number of independent variables:   4
      c18
      c19
      c20
      c21

      Output:

                                    * * * * *

      This test outputs a multiple correlation coefficient and the
      best-fitting linear regression equation using all the independent
      variables. The coefficients for each variable are given and their
      standard errors. These are used to produce a t statistic and
      two-tailed significance for the independent correlation of each
      variable with the dependent variable. Note that this will vary
      according to which other variables are included in the analysis.
      An overall two-tailed probability derived from an F ratio of
      variances is also given, representing the probability of such a
      multiple correlation coefficient occurring by chance.

      5.10  COMPONENT ANALYSIS

      Format: Co[mponent] [number of variables]

      Performs principle component analysis between a number of
      variables.

                                    * * * * *

      Example:

      Select function - co

      - Principle component analysis -
      Enter number of columns to analyse:  4
      Input 4 columns (one on each line):
      c19
      c20
      c21
      c22
      Input lower limit of contribution to variance to include component
      into main table (0 for all, 1 for none):  0.05


                                    40




                               EASISTAT.DOC

      Output:

                                    * * * * *

      Principle components are derived (there is no facility to rotate
      them). The contribution of each to the overall variance is
      output, as is the correlation matrix between them and the original
      variables.

      All components contributing more than a certain fraction of the
      overall variance selected by the user are incorporated into the main
      data table as new columns at the right-hand edge of the table. They
      are titled Co1, Co2, etc.

                                    * * * * *

      The orginal variables are not normalised before the analysis
      (they are not altered to have unit variance). The user may do
      this himself if he wishes, otherwise variables with a large
      variance will produce a proportionately large contribution to the
      analysis.


































                                    41




                               EASISTAT.DOC

      Chapter 6           FILE MANAGEMENT FUNCTIONS

      6.1  DATA

      Format: d[ata] [SAVE] [filename or THIS]

      Reads in data from an ASCII file with the values laid out in columns
      with one row of titles above. To save the data to disk the keyword
      SAVE is used before the filename is given.

      NB If you are working with a narrowed down data set then only the
      narrowed data will be saved. Issue the WIDEN command first if you
      wish to save all the data.

      The data file is simply an ASCII file containing a table of
      numerical values arranged in columns beneath one row of titles which
      determines the width of each column. The titles consist of groups of
      letters or numbers separated by spaces (NB not tabs). There must be
      no blank rows in the table. If a blank row or one beginning with the
      word "END" is found then that will be taken as the end of the data.
      This format allows transfer between EASISTAT data files and files
      used by other software, including spreadsheets, databases, word
      processors and other statistics packages.

      Example datafile (see also EXAMPLE.DAT):

      Age Sex GHQ
      20   1  12
       29 2    13
      22  2   14
      end

      NB "End" is optional if that is the end of the file. The column
      positions are defined by the left-most letter of each label (A,S,G).
      Blank values will be taken as zero.

      Examples:

      DATA EXAMPLE.DAT

      Reads data from file EXAMPLE.DAT

      d s fixed.dat

      Saves data to a file called FIXED.DAT.

      DATA THIS

                                    * * * * *

      Example command file to input and format data:

                                    * * * * *


                                    42




                               EASISTAT.DOC

      To produce a suitable file from a word processor:

      Just write out the data in columns as described above, then save it
      to disc. If your word processor has an option to save the text as
      "ASCII" or "DOS text" then use this option.

      To produce a suitable file from Lotus 1-2-3:

      1. Select "Print", select print to "File".

      2. Select the entire range of values as the "Range" to be printed,
      with a one line set of titles above if you have one. There must be a
      title line above the values in the datafile, so if you do not print
      one out from 1-2-3 then you must add one yourself with a
      wordprocessor afterwards.

      3. Select "Options".

      4. Select margins and set "Left" margin to 0 and "Right" to 240.

      5. Select "Other". Select "Unformatted" output.

      6. Go back to print (by selecting "Quit") and select "Go".

                                    * * * * *

      6.2  OUTPUT

      Format: O[utput] [filename or close]

      The OUTPUT command copies all of the output from EASISTAT that
      appears in the top window of the screen to a file or to the printer.
      This allows you to save your results and study them later, and means
      you can use a word processor to incorporate them into a document
      without having to type them all in again. When you no longer wish to
      send output to the file the OUTPUT CLOSE option closes the file and
      no further output is copied. OUTPUT writes on to the end of a file,
      so if you choose to write to a file which already exists whatever
      was previously in that file will be left as it is and the new
      results will be tagged on at the end. If you have a printer hooked
      up to your computer you should be able to print out to it directly
      by typing OUTPUT PRN.

      Examples:

      Select function -  OUTPUT ANOV0924.OUT

      This command copies output into the file ANOV0924.OUT. If the
      file does not exist then it will be created. If it already exists
      then the new output will be appended to the old file.

                                    * * * * *



                                    43




                               EASISTAT.DOC

      Select function -  OUTPUT CLOSE

      Output will no longer be copied to the file or printer until
      another OUTPUT command is given.

      Example output:

                                    * * * * *

      Comments:

                                    * * * * *

      Advanced tip

                                    * * * * *

      6.3  INPUT

      Format: I[input] [filename or close]

      Causes a command file to be read in. Command files contain commands
      exactly as they would be typed at the keyboard.

      Example:

      Select function -  i
      Enter name of file to read input from (KEY for keyboard): demo

      The file on your disk called DEMO is a command file. Please study it
      to see how it works. Note that you can also run a command file when
      you first run EASISTAT by typing eg EASISTAT DEMO. This causes
      EASISTAT to read in the command file called DEMO. This facility
      means EASISTAT jobs can be run as part of a batch file.

                                    * * * * *

      6.4  LOG

      Format: Lo[g] [filename or close]

      Produces command files by copying keyboard input to a file. This log
      file can then be read in again as a command file, or it can be
      edited and elaborated first. This is a very useful way to get
      started creating command files.

      Examples:

      Select function - log stat0927.log

      Copies all commands into STAT0927.LOG.




                                    44




                               EASISTAT.DOC

      Select function - log close

      Closes file so that no further commands will be copied. Like OUTPUT,
      LOG writes onto the end of a pre-existing file.

      6.5  ECHO

      Format: E[cho] text

      Echoes input to output, allowing comments and titles to appear in
      output files, or for command files to explain themselves on
      screen as they run.

      Example: e    The title of the next test is this

      See the DEMO file for examples of the use of the ECHO command (the E
      at the start of most lines is invoking ECHO).

      6.6  PAUSE

      Format: P[ause]

      Produces a pause in a command file.

      Example:

      p

      Ouput:

                                    * * * * *
























                                    45




                               EASISTAT.DOC

      Chapter 7                   SPECIAL FUNCTIONS

      7.1  HELP

      Format: H[elp]

      The HELP function simply outputs a list of all the functions
      available, together with a brief reminder of their syntax. You
      may want to use the OUTPUT command to print this list out on
      paper so you can refer to it when you do not have the manual
      handy.

      Example:

      Select function -  h

                                    * * * * *


      7.2  SYSTEM

      Format: Sy[stem] [command or program]

      This allows you to issue commands to the operating system or even
      run other programs, provided there is enough memory available.

      Example:

      Select function - sys dir

      Produces a directory listing.

      When the command has been executed then EASISTAT will wait for a
      keypress before continuing.

      Comments

                                    * * * * *

      7.3  SCREEN

      Format: S[creen]

      This simply redraws the EASISTAT screen if an error has occurred
      which has messed it up.

      Example: SCR

      7.4  ARITHMETIC

      Format: Ar[ithmetic] [sum]

      This function evaluates arithmetical and logical expressions.


                                    46




                               EASISTAT.DOC

      Examples:

      Select function - ARITH
      5 +5*38
      2.6/7+(3.5-.6)pow(0.5)

      Select function - ar 5 +5*38

      Or we can use the probability look-up functions, e.g. to find the
      significance of a Chi-squared of 13.6 with 2 degrees of freedom:

      Select function - ARITH
      13.6PX2

                                    * * * * *

      7.5  QUIT

      Format: Q[uit]

      Quits EASISTAT.

      Example:

      Select function -  q
      Quit EASISTAT - sure?
      y




























                                    47




                               EASISTAT.DOC

      Chapter 8                ERROR MESSAGES AND BUGS

      8.1  LIST OF ERROR MESSAGES WITH THEIR MEANINGS

                                    * * * * *

      8.2  WHAT TO DO IF YOU GET AN ERROR MESSAGE

      There are essentially two different kinds of error message. One
      is caused by the user making a mistake in what he types in - a
      syntax error, a spelling mistake or giving the wrong name or
      pathname for a file. The other kind is when the computer runs out
      of memory or runs into mathematical problems like trying to
      divide by zero. Things are not quite so clear-cut, because in
      fact the commonest reason for the program to produce the second
      kind of error message is also because the user told it to do
      something silly, like make a chi-squared table with zero rows. We
      have tried to trap most of these errors, but a few have got through.

      If you get an error message, first check carefully that you have
      not made a typing mistake. If not, and especially if you get one
      of the "out of memory" messages, then it may be that you are
      exceeding the program's capacity. Although we have tried to guard
      against it, there is a risk that the program may "hang up", which
      means that absolutely nothing at all happens when you push any of
      the keys, except possibly for a beeping noise. Should this happen
      there will be nothing you can do except reset the computer or
      turn it off and on again. Because of the risk of this, if you get
      an error message which you cannot otherwise explain we advise you
      immediately to save your data to a file and to close your output
      and log files. Do not save your data to the same file that you
      read it from, but to a new file with a different name. All these
      precautions are to minimise the risk of an error in your program
      damaging ("corrupting") any of your files or leaving you stuck
      unable to save your data.


      8.3  RUNNING OUT OF MEMORY

      If you get an "Out of memory" message the most likely reason is
      not that the computer is running out of memory, but that you have
      asked it to do something silly which requires zero memory, so
      check this first. If you get an "Out of stack memory" message
      then it may be that you are asking the program to perform an
      especially complicated calculation, though to be honest we don't
      think that this is likely to happen. However should it occur
      first check that you have not made a mistake and then try to
      simplify what you are asking the program to do, perhaps by doing
      it in stages.

                                    * * * * *

      EASISTAT tries very hard to use as much as of the computer's
      memory as it can, and to do this it ends up putting things in all

                                    48




                               EASISTAT.DOC

      sorts of nooks and crannies. If you find that you are running out
      of memory with a particular function it is possible that the
      following procedure may help:

                                    * * * * *

      8.4  BUGS AND CRASHES

      Sometimes if there is something wrong with EASISTAT or one of the
      other programs your computer is running at the same time then
      your computer can "hang up" or "crash". If the computer hangs up
      or crashes then none of the keys you press will have any effect,
      except sometimes to make a beeping noise. If this happens you are
      probably going to have to reset the computer, or turn it off and
      on again. Your computer will not be damaged in any way, but any
      data or results not saved will be lost. Before you do this check
      the following points:

      1. Make sure the program is not just performing a long
      calculation.

      2. Make sure you have not tried to send something to the printer
      or "PRN" without having the printer connected, turned on and on
      line. If you have then you may have to wait a couple of minutes
      for the printer to "time out" and display the "Not ready writing
      device PRN" message.

      3. Make sure you have not tried to read or write to a disk which
      is not in a drive or which has the drive door open. If you have
      done this then it should time out quite quickly and give you an
      error message, but it's worth checking.

      If none of these things have happened then the program has
      crashed and you will have to reset the computer and start again.
      Try to see if you can see what caused the crash.

      Bugs

      A "bug" is something wrong with the way that the program is
      written which causes it to behave in a way other than that
      intended or expected. We aim to correct as many bugs in EASISTAT
      as possible, and we aim to inform users of any uncorrected bugs
      of which we are aware. However in such a large and complex
      program it is always possible that some bugs may have crept
      through of which we are unaware, and so we ask users to inform us
      if they find one of these so that it can be corrected or at least
      so that other users can be warned of it. Sometimes a program can
      behave in the way that the programmer wants it to, but that may
      not be the way in which a particular user expects it to behave.
      This turns into an argument about whether something is a "bug" or
      a "feature". In this manual we have tried to clarify as far as
      possible exactly what the program does, especially where it
      behaves in a way which might not be expected.


                                    49




                               EASISTAT.DOC

      Known bugs

      See the section on "Operator precedence" for a description of a
      bug in the way logical and arithmetic expressions are handled.

      Sometimes the error message produced by EASISTAT does not give a
      very clear picture of what the actual problem is.

      If the program runs out of room when writing a file to disk then
      it may not inform you, but leave the file incomplete. Therefore
      always make sure there is plenty of room available on disk (by
      using the DIR command available from the operating system).

      It is possible for mathematical overflow errors to occur when
      performing some of the significance tests, in particular those in
      which a value is divided by its standard error and the result is
      taken to approximate a t statistic as is done for the regression
      tests. With large numbers of values the significance test can then
      amount to for example the probability value of t = 60 with 1000
      degrees of freedom. This is clearly highly significant, but
      attempting to calculate the exact probability cause a mathematical
      error. The "correct" value of 0.0000 will still be given, but an
      error will be reported. This is harmless, but disconcerting if one
      does not know the reason for it.

      If you keep trying to add rows or columns until EASISTAT runs out of
      memory so that the data table reaches its maximum size, then running
      the data editor immediately can sometimes cause the computer to
      crash. The reason for this is obscure. It only occurs if you attempt
      to exceed the program's capacity (with thirty columns well over
      seventy thousand data points can be accommodated in around two
      thousand five hundred rows), and it seems only to happen if the EDIT
      command is the first command given after the "Out of memory" error
      message. Should you get such a message we advise you to first issue
      an innocuous command like TITLES and to make sure you save any
      unsaved data.

      Unknown bugs

      Apart from causing the computer to hang up, other symptoms of
      bugs are that the program produces long strings of meaningless
      characters and beeps, or very large long numbers which are
      obviously nonsensical. Bugs may also simply produce incorrect
      answers. We are not aware of any that do this, but if you suspect
      their existence then please let us know at once.

      We would like to fix any bugs in the the program, so please write
      to us to let us know of any circumstances which produce a crash
      or garbage output. If you cannot see why the program should have
      gone wrong at this point then please supply us also with the
      following information (on a disk if possible - we will return
      it):

      1. Contents of your data file.

                                    50




                               EASISTAT.DOC


      2. Exact sequence of commands leading to crash.

      3. Make and model of your computer, plus peripheral devices.

      4. Contents of you AUTOEXEC.BAT and CONFIG.SYS files, and the
      names of any memory-resident programs you have loaded.

      5. Version of DOS (find this out by entering VER at the DOS
      prompt).

      6. Version of EASISTAT (displayed on title screen).











































                                    51




                               EASISTAT.DOC

      Chapter 9                   ACKNOWLEDGMENTS


      EASISTAT programmed by Dave Curtis. Thanks to Allan Curtis for his
      valuable support and advice. The statistical functions are
      implemented from descriptions in Statistical Methods in Medical
      Research by P. Armitage and G. Berry, 2nd edition, Blackwell
      Scientific Publications, 1987 (highly recommended). The program was
      written in C and C++ and was compiled with the Zortech compiler
      (highly recommended). The incomplete beta function and matrix
      decomposition routines were derived from Numerical Recipes in C by
      W. H. Press, B. P. Flannery, S. A. Teukolsky and W. T. Vettering,
      Cambridge University Press, 1988 (highly recommended).

      DESQview is a trademark of Quarterdeck Office Systems. MS and
      Microsoft Windows are trademarks of Microsoft Corporation. IBM and
      PC are trademarks of International Business Machines Corporation.
      PC-Write is a trademark of Quicksoft Incorporated. PC-File and
      PC-File:dB are trademarks of Buttonware Incorporated. Lotus 1-2-3 is
      a trademark of Lotus Development Corporation.




      We would welcome any comments, criticisms, or suggestions for
      improvements. New functions will be continually added, and if
      anyone has any special requests we will do our best to accommodate
      them.



      Please display the following notice in your department and pass
      copies of the program on to your colleagues. Thank you.



                                 Good luck.
                                                      ARC Scientific Ltd.
                                                      December 1988


      STOP PRESS: A prototype version of EASIPLOT, a graph
      drawing package, is now available for use with
      EASISTAT. It is also available as Shareware and is
      sent out free with EASISTAT to all registered users.
      The documentation for EASIPLOT is contained in a
      separate file called EASIPLOT.DOC. By default,
      EASIPLOT now uses EASIPLOT and not PCG2 to draw its
      graphs.







                                    52









                                   EASISTAT




      EASISTAT is a statistics package that will run on IBM PC's and
      compatibles. It performs simple data management and statistics and
      includes the following tests:

      Mean, mode, median, standard deviation, variance, standard error of
      mean, Chi-squared test, Fisher's exact test, Wilcoxon's rank sum,
      Kolmogorov-Smirnov, Kendall's rank correlation, T-test, analysis of
      variance, linear regression, correlation coefficient, multiple
      linear regression and principle component analysis. Calculator and
      table look-up functions are also available. A total of about seventy
      thousand data points can be accommodated in practically any number
      of rows or columns. A variety of graph types can also be displayed.





      EASISTAT is distributed as Shareware, which means that anyone who
      wants a copy to have a look at can have one free. If you would like
      a copy please contact:





                  ------------------------------------------





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                   (now includes EASIPLOT)
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       _____________________________________________________________
                  |                        |   Price   |
         Number   | Description            |(inclusive | Total price
       of copies  |                        |  of VAT   |
                  |                        |& shipping)|
       ___________|________________________|___________|____________
                  |                        |           |
                  |                        | 30 pounds |
                  | EASISTAT  program      |  sterling |
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