MAKING THE MOST OF LOGISTIX

Mike Williams offer some advice on the use of Logistix, the first and maybe one of the best spreadsheets for the Archimedes.

I have been using Logistix regularly ever since I first reviewed it for RISC User (Volume 1 Issue 3). Although I have had the opportunity to try other spreadsheets as they have appeared (Matrix-3, GammaSheet and PipeDream for example), I have so far found no real incentive to change. The purpose of this article is to look at some of the more frequently used aspects of Logistix, and to present the fruits of my experiences so far.

Logistix offers four different applications in a single package: spreadsheet, database, presentational graphics and time management. I have to say at the outset, that apart from entering a few worked examples, I have personally found no use as yet for the last. I have used the database facilities, but I find that a separate database system better satisfies my needs. Thus this report will concentrate on the spreadsheet and graphics capabilities, which are probably the most important and most commonly used parts of the package anyway.

It seems to me that there are three key features when using a spreadsheet program. How easy is it to create a spreadsheet in the first place? How easy is it to update the data in your spreadsheet once entered? And, finally, and this applies right from the start, how easy is it to change the structure of your spreadsheet? Logistix works well on all counts, and it is the convenience of its user interface which I feel is largely responsible for this.

KEYBOARD INPUT

Logistix may seem rather tame compared with some of the WIMP-based applications around. No mouse to click away with here. All user input is via the keyboard. The cursor keys provide basic movement around the screen, but Page-Up, Page-Down, F9 and F10 to move a whole screenful at a time (up, down, left, right) are also very useful. My main application has grown as time has passed, and I have a number of sub-spreadsheets located in different areas of the available worksheet.

I've also set up graphics displays for most of these sub-sheets as well, again using different pages. It helps here to plan ahead and be consistent (for example, always keep your graphics programs in the first free page to the right of any spreadsheet). Even when you do, you still sometimes find you have located a blank area of the sheet, and the use of the Home key to return to the top left-hand corner of the sheet is a convenient way of restoring normality.

Data, i.e. numbers or text, is just entered straight in, being placed by Logistix in the current cursor position. Although you can use Return to terminate data entry, it is usually more convenient to use a cursor key, which not only fixes that piece of data, but allows you to move on automatically to the next input position. However, if you edit a field (/E) you must terminate the edit process with Return. You also have to get used to the IBM-style back-arrow key for deletion, and not the more usual BBC Delete key (which seems to have the same effect as Escape here).

Logistix is generally quite good at deciding what category of input it is being presented with. Text, numbers and expressions can often just be typed in. But other classes of input, such as graphics commands, need to be specified as such (a preceding comma for a graphics command for example). When you are trying to find why some aspect of your sheet is not working, do check that every entry is of the right type.

HINT

I find with my own application a not infrequent need to update a number by adding a further value to it. Perhaps because I'm lazy, I use the edit facility to replace the original number in a cell by an expression which is the original number plus (or minus) the new number. I then use the replicate command (/R) with the values option (V) to replace the expression in the cell by the value of the expression. The key sequence is:
/RV,<Return>

Logistix helps, because as you move the cursor about the screen, a display line at its foot not only shows what is really in each cell (a formula for example, when otherwise all you would see is the value which results from that formula), but Logistix also tells you into which category the cell contents fall. Enter the PIA command to specify a pie chart, and the command will look the same in the spreadsheet whether the three letters are entered as text or as a graphics command. The difference can be the difference between success and failure, so don't get too complacent about input.

REPLICATION

One of the most useful features of any spreadsheet has to be its ability to replicate (copy) values or formulae across cells, rows, columns or complete blocks of cells. I have not found Logistix wanting in this respect, though I have found difficulty in always getting things to work as I would wish.

A major convenience of Logistix is that you seldom if ever need to enter cell references from the keyboard. Moving the cursor around the screen picks these up automatically. Thus if you want to replicate the contents of one column to a neighbouring column, move to the top of the column to be replicated (its cell reference appears automatically on the input line at the foot of the screen), and press:
/RR:<foot>,<start>Return
where <foot> means move the cursor to the foot of the column to be replicated, and <start> means move to the first position of the new column.

Note that when replicating a column or a row you only have to specify the first cell of the new location. It is worth practising with the use of the replicate command as you are likely to use it more than most.

Another useful feature of Logistix is that cell references can be specified as absolute (upper case letters) or relative (lower case letters). However, to make use of this feature you must also select the correct setting in Global Options (/G), otherwise, like me initially, you will begin to feel that this feature is a figment of the documentation.

For example, if at the foot of column A you have the entry +SUM(A1:A9) in cell A10 (the '+' specifying an expression), and you replicate the column A1:A10 into column B, the summation will remain quite unaltered (with the correct global option set). But use the expression +SUM(a1:a9) and on replication into column B this is converted to +SUM(b1:b9). Relative cell references throughout are the norm.

Another example of replication uses the values option, and converts a formula into its corresponding value. I find this quite useful to fix a value at a certain point in time to form an historical record from then on (see also Hint).

FORMATS

Although Logistix as might be expected provides a good variety of formats, I have found some frustrations. The format command (/F) allows you to specify the width of a column and the format in which numbers, the lifeblood of any spreadsheet, will appear. You can select one or more rows or columns, or a block of cells, and apply any selected format to just that group of cells. However, fewer options are available when dealing with a block of cells than are available with rows and columns. This is unfortunate.

A format (e.g. number of decimal places) applied to a column affects every single cell on the spreadsheet in that column. Given the paged approach to the use of the spreadsheet, I find I want different formats for different parts of the same column. But formatting a block of cells, which is what you end up doing, does not, for example, permit the number of decimal places to be specified (or fixed), a nuisance when dealing with some figures.

Eight different formats are available for financial data, including the facility for negative amounts to appear automatically but disconcertingly in red (other, perhaps kinder, formats are also available).

GRAPHICS

I have used the graphics options to display parts of my spreadsheet in either barchart or pie chart format. This does not prove too difficult if you follow the examples given in the manuals. However, I find that most of the displays are quite crude, demonstrating Logistix' regrettable inability to take advantage of the colour range and sophisticated graphics of the Archimedes, while any text captions on a standard colour monitor are well nigh unreadable. Do make sure that the Logistics disc is inserted before displaying any graphs so that any fonts can be correctly accessed. Logistix gets rather unhappy otherwise. All in all, I feel that the graphics are a considerable disappointment.

FINAL THOUGHTS

Much of what I have covered has derived, as I said at the start, from my own frequent use of Logistix to maintain what I feel is a reasonably comprehensive spreadsheet application. For much of what I need, Logistix is ideal. However, I certainly do not claim to know everything there is to know on Logistix, and indeed I would welcome any feedback or further information from members, who may be able to add to my own experiences with Logistix for the benefit of others.

Note: Logistix is published by Acorn Computers, and costs £113.85 inc. VAT (available at 5% discount to RISC user members when purchased from BEEBUG).