				Gplot
				-----

    The graph plotting and mathematical package for the Psion series 3
    ------------------------------------------------------------------


Installation
------------

Using the provided INSTALL.OPO program is recommended, however if you 
wish to manually install GPLOT the following is required

Create \APP\GPLOT and \OPD\GRAPH directories

Copy GPLOT.OPA to \APP\GPLOT.OPA
Copy XGPLOT.OPO to \APP\GPLOT\XGPLOT.OPO
Copy GPLOT.HLP to \APP\GPLOT\GPLOT.HLP
Copy SYS$HELP.OPO to \OPD\SYS$HELP.OPO (this will not appear under your 
OPO icon)

Install Gplot from the system screen using Psion+I.


Use of Gplot
------------

Gplot is shareware, this means if you use it you should register. 
Registration will bring you updates for free, along with notification, 
by email. Or for a minimal shipping charge by snail mail.

Gplot is not crippled in any way, your only incentive to register is
your concience and the desire to persuade me to produce more
software.  Registration also removes the irritating reminder that is 
displayed on exit.  It is also guaranteed to give a warm glot inside! 
See the Registration section in this text or the details within the 
program for more information.


Current Functions
-----------------

3 Windows for graphs, 1 full screen 2 half screen windows.

Plotting of any function that can be evaluated in "Calc".

Plotting of data points.

Linear fits of data points, with gradient, x intercept, y intercept
and RMS error calculation.

Manipulation of data points by functions.

Editing, modification, deletion and display of data points.

Numerical integration of functions using simpsions rule.

Solution of equations by Newton Raphson method.

Tracing of plotted functions with cursor.

Option to add scales at user defined intervals to the graphs.

Info screen with details of graphs.

Solution of simultaneous equations for systems of up to 32 variables.

Bring to and from Spreadsheet


Use of Gplot
------------

After installation the Graph icon will appear on the system screen,
below it will be listed any data files.  These files are held in the
\OPD\GRAPH directory (this will be created if it doesn't exist).  Pressing
Enter on any of these files will open it and start Gplot.

The active data file will be displayed in the status window on the
right of the screen, if you do not wish to use the file functions
then creation of a dummy file with no data points will safeguard
data.

Pressing help will bring up information on all functions, these may
be accessed by any of the following methods, pressing Menu, pressing
Psion+<key> where <key> is the hotkey listed to the right of the entry 
in the Menu or just <key>.  Exit (Psion+X) is the only function that 
cannot be accessed by a single keypress.  The Diamond key cycles through
the 4 avaliable windows, it starts with just the status window avaliable,
as more windows are made avaliable then these will be cycled through.

Details of the functions follow.



FILE
----


New (Psion+N)

Creates then opens a new data file, closing the current open file


Open (Psion+O)

Closes the current then opens an existing data file


Bring Data (Psion+B)

This will bring highlighted data from the Spreadsheet into the current 
data file for plotting and fitting.  The data will be echoed to the 
system screen as it is copied over.

Export Data (Psion+Shift+E)

This highlights the current data file for export, the data can now be 
copied into a spreadsheet file using Bring (Psion+B).  The operation can 
be cancelled by pressing Esc.


MATH
----


Info (Psion+F)

This pops up a dialog with details of the ranges and functions of the
graphs.


Integrate (Psion+I)

This integrates a function (either from one of the graphs or
specified) using Simpsons rule


Newton-Raphson (Psion+W)

This solves equations using the Newton Raphson method, points either
side of the desired root should be specified, these can be determined
from the graph


Matrix Solution (Psion+Q)

This solves sets of simultaneous linear algebraic equations, the
coefficients are input in equation order,
followed by the solutions to the equations.  Up to 32 variables are
supported, if anyone wants to use greater than 32 variables then let
me know and I'll recode it.  Good luck to you too!



GRAPH
-----


Plot Graph (Psion+G)

Allows a function to be plotted on one of the 3 avaliable windows. 
This is any function that can be evaluated in Calc, acceptable
variables are x,X,y,Y,q,Q these are all converted to q or Q for speed
of calculation.


Plot (Psion+P)

Plots the data in the current open file


Trace (Psion+T)

This allows the function in a chosen window to be traced, keys while
tracing are as follows:

With CapsLock ON or Shifted cursors

	Arrow keys move the cursor around the screen, Control jumps the
cursor 5 pixels

With CapsLock OFF

	Left and Right move along the function

	Psion+Z and Psion+Shift+Z zoom in and out of the graph centred on
the cursor.

	Enter redraws with the cursor now as the screen centre.



Ranges (Psion+R)

This allows you to set the ranges on the axis of the graphs


Label Axis (Psion+Shift+B)

This puts tick marks on the axis at specified intervals



DATA
----


Linear Fit (Psion+L)

Fits a line of best fit to the data in the current file


Display (Psion+D)

Displays the data in the current open file


Modify (Psion+M)

Allows a function to act on X and Y values in the current file. 
There is  special case X=Y this transposes the two ranges.


Edit (Psion+E)

Allows addition, modification or deletion of points in the current
file.


SPECIAL
-------


About (Psion+A)

Information about Gplot and registration.


Register (Psion+Shift+R)  This only appears on the unregistered 
evaluation version.

Allows entry of Name and code to Register Gplot


Set Preferences (Psion+Q)

This allows various options to be set, if "Save graphs on exit" is
chosen then then the graph functions and ranges will be saved on
exit.

If the resolution is increased the pixel jump between recalculations
will be increased, greatly increasing the speed of plotting, but
decreasing the number of points plotted so reducing the accuracy of
highly oscillatory functions.  A resolution of 4 or 5 is recommended as 
being a reasonable compromise between speed and accuracy.


Close Windows (Psion+Shift+K)

This destroys all currently open graph windows, recovering the memory 
used by them.  To hide the windows the Diamond key can be used to cycle 
through different views.

Exit (Psion+X)

Close open files and exit Gplot.



Disclaimer
----------

Although I have fully tested this program and see no reason why it should
cause problems I would still like to issue the following disclaimer. 
This program is used entirely at the users risk, and any fault or
loss of data caused by the use of this program will be the 
responsibility of the user and no liability will be placed upon M.Millar.


Registration
------------

Registration costs 15 in the UK or $25 in the US, US registration is by 
the GO SWREG service on CompuServe.  UK registration can be made by 
cheques payable to "M.C.Millar" and posted to 

M.C.Millar
The White House
28 Water End
Clifton 
York
YO3 6LP
United Kingdom

Credits
-------

Thanks to David Wood at Psion for the assistance with the use of the OO 
programming for the EVAL speed enhancements.  Tom Dolbilin for the OPL 
help system, this can be used with other OPL programs, mail myself or 
Tom on CompuServe or CIX (Tom : Compuserve 72730,1176 Me : Compuserve 
100021,3354 or millar@cix.compulink.co.uk) for more details.  Dennis 
Lefebvre for the loan of the S3a programming manual before I had my S3a.
All my beta testers, and all the users that have registered and come up 
with recommendations for new features in Gplot.


History
-------


Version 0.82-0.83, added Escaping from graph plotting

V0.83-0.83.1, Fixed the jump to graph plot after linear fit.

V0.83.1-.2, Fixed the bug with -ve RMS means

V
0.83.2-.3, Added x intercept display to Linear fit.

V0.83.3-.4, Fixed bug with plotting fitted graphs to windows other
than Full screen.  Speeded up graph plotting by reducing number of
significant figures to be parsed.

V0.83.4-.5, Added option to set X ranges before autoranging

V0.83.5-.6, Code refinements, commenting of code

V0.83.6-1.0, Made Gplot a type 2 APP, added trace, scales, zooming
functions, Simultanous equation support, further commenting and
algorythm improvements.  Shareware now. Reorganised Menus to be more 
Psion compliant.

V1.0-1.1 Fixed problem with directory creation on startup and new
file from system screen creation.  Translated mdified S3a version.

V1.1-2.0a Major speed revision with optimizations for S3a use, including 
enanced EVAL parsing.  Added diamond key handling, added link paste 
between Spreadsheet and Gplot.	Registration handling.	Included use of 
Tom Dolbilin's SYS$HELP.OPO for help system.

