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- Readme file for Trace v1.0
-
- Trace is an OPL plotting program which is intended to add to the Psion 3a
- the graphical features that are surprisingly missing in the built-in
- calculator. Trace is a freeware, so you can use it and distribute it freely.
- To install it, just drop the Trace.opa file in the \APP directory and install
- in the system as usual. Created dumps or bitmaps files will appear in \OPD.
- Trace occupies 13 Kb of disk space, and requires a minimum of 25Kb of RAM.
- If you find it useful, please let me know at the following e-mail address:
- perroud@messv1.univ-pau.fr.
-
- Trace was developped on a french version of the Psion 3a system, and is
- "speaking" french. It has not be tested on other versions. I decided to
- keep its native language to emphasize the existence of non-english users
- and fans of this marvelous little thing. I think that even non french-
- speaking Psion users can easily take advantadge of it. If this is not the
- case, I may consider to translate it into an english version, so let me
- know your feelings through my e-mail address.
-
- Trace can plot either mathematical functions or 2D data stored in a text file,
- or combinations of both types of graphs. The functions are input from the
- keyboard, and can use only OPL valid expressions, since the actual calculation
- is done through OPL eval() function. When entering the function, each occurence
- of the variable (say x) should be replaced by a pair of brackets (). The
- function is evaluated at regular intervals, according to the value of xmin,
- xmax and the number of points. Predefined defaults value are 51 points between
- x=0 and x=1. These values can be changed through the Axes and Options menus.
- The datafiles should be text files organized in tab separated columns,
- containing pairs of x and y values. The file can consisted of more than two
- columns; when entering the data, the column number can be choosen for x and y.
- There is no requirements on the order of the data columns. When reading the
- file, xmin and xmax are automatically set to the actual limits of the data.
-
- Trace proposes 5 types of graphs, which correspond to the 5 items of the
- first menu (TracÄ):
- - TracÄ fonction: allows to plot a function entered at the keyboard with
- the preset x range and number of points.
- - TracÄ donnÄes: allows to plot a 2D datafile with symbols and connecting
- lines if desired.
- - ModÅle numÄrique: allows to plot together a datafile and a model curve
- given by a set of x-y pairs in a second text file. The format of the model
- text file is the same as the format of the datafile. The x range of the
- plot is set by the x range of the datafile, whatever the x range of the
- model file.
- - ModÅle analytique: allows to plot together a datafile and a model curve
- given as a function and entered at the keyboard in the same manner as the
- simple function. In that case, the function is evaluated in the x interval
- defined by the datafile.
- - Fit polynome: allows to plot together a datafile and a model curve given
- by the best fit polynomial function, calculated by a least-squares method.
- The degree of the polynom can be fixed between 1 (linear fit) and a maximum
- of 6 (limited for performance considerations). Once calculated, the best fit
- function is proposed as the default function in the other function plots.
-
- Apart from the plots, Trace proposes a few other utilities, like saving the
- plot in a PIC file, saving the values calculated for the functions in a text
- file, or getting from the screen the x-y coordinates of any point. This last
- feature is available only after a plot has been done, and is started by the
- diamond key. A cursor is displayed and can be moved with the arrows. The
- increment of motion can be adjusted by the psion-arrows combinations. When
- the cursor is positionned, the x-y coordinates are displayed by the enter
- key. The esc key allows to cancel the operation.
-
- A limited help is available on line using the Help key, or the Aide item of
- the Special menu. An abridged version of this file is then displayed. When
- the diamond feature is active, short help messages are also displayed when
- using the Help key.
-
- Plot options:
-
- Trace will produce a new plot each time you select one of the 5 items of the
- TracÄ menu. In each dialog, previous choices will be offered as defaults, or
- predefined values for the first plot. The plot will then be achieved using
- the current values of the graphical parameters. If you want to change these
- parameters, use the corresponding menu items described below, and then redo
- the plot from the menu or its keyboard shortcut.
- - Axes menu items:
- * Type: allows to change each axis from linear (default) to logarithmic.
- * Bornes auto: When set, the y range is automatically adjusted (default).
- * Borne x: allows to specify the x range of the plot (default 0-1).
- * Borne y: allows to specify the y range of the plot (default automatic).
- - Options menu items:
- * Nb points: allows to specify the number of points where the functions
- will be calculated (default 51). The time required to produce a plot is
- very dependant of that parameter. It was therefore limited to 1001.
- * Zoom: allows to zoom in a portion of a plot. This option requires a
- plot has already been made. When you select it, you have to choose on the
- screen the lower left and upper right corners of the rectangle you want to
- zoom in. Move the cursor to the first corner, hit enter, then move to the
- second corner and enter again. The rectangle will be drawn and you are
- asked for confirmation. If you confirm, the last plot will be redone.
- * Preferences: allows to change some graphical parameters, including the
- size of the plot, size of symbols, connecting lines or the number of
- decimals in the axes labels. You have also the possibility to ask for
- dumping the x-y pairs calculated for the functions plots in a text file
- whose name will be trace.txt. The format of the file allows to replot it
- as a datafile, what can save the time necessary to recompute these values.
- * DÄfauts: switch back all parameters to their built-in default values.
- - Special menu items:
- * Info: displays the current values of the graphical parameters.
- * Aide: displays a short description of Trace main features.
- * Sauve plot: dumps the current plot in a bitmap file (trace.pic).
- * Quitte: quit Trace.
-
-