GRAPHER - Graph plotting utility. 

System requirements
-------------------
Win9x, 2000 or NT

Installation information
------------------------
Just unzip the file "graph.zip" and run "graph.exe" by double-clicking
on it. No installation is required.

About
-----
GRAPHER, Version 1
Created by
  Akshay Kulkarni,
  Sophomore,
  Department of Physics,
  Indian Institute of Technology, Bombay.
e-mail: akshaykkulkarni@hotmail.com

Runtime information
-------------------
  Sometimes, if a graph takes too long to plot, the entire window may
become white. But this does not mean that the system has crashed. The
graph will appear on screen when it is completely plotted. Meanwhile,
you can work with other applications which are already open.

Introduction
------------
  GRAPHER is an easy-to-use graph plotting utility. With it, you can
plot 2-D graphs in explicit, parametric or polar form, autoscale or
zoom the view. You can plot up to 20 functions at a time. A large
number of mathematical functions are available. There is a built-in
calculator, and a colour index of all functions with their respective
colours. Graph tracing is possible, and the coordinates of the tracing
cursor are shown.

Plotting graphs
---------------
  Just enter equations into the box titled "2-Var. Equations(max.20)".
If the box is not visible, click on "EQUATIONS". Enter only the right
hand side of the equation f(x)=.... for explicit equations, or of the
equations x(t)=...., y(t)=.... separated by a semicolon for parametric
equations, or of the equation r(t)=.... ("t" means "theta") for polar
equations. Then click the "PLOT" button. Clicking the "CLEAR LIST"
button clears all equations, and the "CANCEL" button cancels any
changes made to the equations. Clicking "EQUATIONS" again causes the
"Equations" box to disappear.
  You can also click anywhere on the graph sheet to plot.

Changing the equation type
--------------------------
  Click "OPTIONS" and choose "Change Equation Type". Then select the
equation type you want. The "Equations" box will change to accept the
new type of equations.

Changing the settings of the graph sheet
----------------------------------------
  To adjust the x-range, y-range, t-range etc., click "OPTIONS" and
choose "Change Plot Settings". A box will appear. Make the changes you
want. You don't have to enter just constants here. You can enter any
mathematical expression. Double-clicking on any field restores the
default value of that field. Clicking "DEFAULT" restores all fields to
their default values. Then click "OK", and then click anywhere on the
graph sheet to plot the graph.

Zooming
-------
  Choose "Zoom" from the "OPTIONS" menu. Adjust the zoom settings to
your preference, and then click "OK". Here also, the "DEFAULT" button
restores default values, and double-clicking on the zoom factor field
restores its default value.

Autoscaling
-----------
  Choose "Autoscale" from the "OPTIONS" menu. The x- and y- ranges will
automatically adjust to fit the entire graph.

Undoing
-------
  Choose "Undo last plot" from the "OPTIONS" menu. The last plot will
be undone.

Colour Index
------------
  If there are too many graphs, you won't know which graph belongs to
which function. The colour index solves this problem. Choose "Colour
Index" from the "OPTIONS" menu. It shows, in a box, each function along
with the colour of its graph.

Calculator
----------
  This is a simple calculator. Choose "Calculator" from the "OPTIONS"
menu. Enter any mathematical expression in the white box, then press
Enter or click "GO". The result appears in the "Result" box, and is
stored in a variable called "ans" which you can use anywhere.

Tracing
-------
  A special "trace" cursor appears on the graph when a graph is
plotted. Use the scroll bar at the bottom of the window to trace. The
box at the top displays the position of the trace cursor. To trace some
other graph, change the number in the box titled "Tracing eqn. no.". If
you don't want to trace, click the "DON'T TRACE" button. Its name will
change to "TRACE", and the tracing cursor will disappear. The position
box will now show the position of the mouse cursor as it moves over the
graph sheet. To start tracing again, click on "TRACE".

List of available functions
---------------------------
In the following, "expr" is any mathematical expression.

   Basic operations
   ----------------
   Operation     Description       Syntax
   ---------     -----------       ------
     +           addition          expr1+expr2
     -           subtraction       expr1-expr2
     *           multiplication    expr1*expr2
     /           division          expr1/expr2
     ^           power             expr1^expr2

   Algebraic functions
   -------------------
   Function      Description       Syntax
   --------      -----------       ------
   sqr, sqrt     Square root       sqr(expr), sqrt(expr)
   abs           Absolute value    abs(expr)
   sgn           Sign(-1 for -ve,  sgn(expr)
                   +1 for +ve, 0
                   for 0)
   int           Greatest integer  int(expr)
   fac           Factorial         fac(integer expr)
   log           Logarithm (to     log(expr)
                   base 10)
   exp           Exponent (e to    exp(expr)
                   the power expr)
   sum           Summation         sum(a, b, expr)
                                   where a and b are positive integers,
                                   and expr is the expression to be
                                   summed. The variable of summation is
                                   n. eg. To write
                                   summation(n=1 to 20)sin(nx),
                                   enter
                                   sum(1, 20, sin(nx))

   Trigonometric functions
   -----------------------
   Function      Description       Syntax
   --------      -----------       ------
   sin           sine              sin(expr)
   cos           cosine            cos(expr)
   tan           tangent           tan(expr)
   cot           cotangent         cot(expr)
   sec           secant            sec(expr)
   cosec         cosecant          cosec(expr)
   asin          inverse sine      asin(expr)
   acos          inverse cosine    acos(expr)
   atan          inverse tangent   atan(expr)
   acot          inverse cotangent acot(expr)
   asec          inverse secant    asec(expr)
   acsec         inverse cosecant  acsec(expr)

   Hyperbolic trigonometric functions
   ----------------------------------
   Function      Description                     Syntax
   --------      -----------                     ------
   sinh          Hyperbolic sine                 sinh(expr)
   cosh          Hyperbolic cosine               cosh(expr)
   tanh          Hyperbolic tangent              tanh(expr)
   coth          Hyperbolic cotangent            coth(expr)
   sech          Hyperbolic secant               sech(expr)
   csech         Hyperbolic cosecant             csech(expr)
   asinh         Inverse hyperbolic sine         asinh(expr)
   acosh         Inverse hyperbolic cosine       acosh(expr)
   atanh         Inverse hyperbolic tangent      atanh(expr)
   acoth         Inverse hyperbolic cotangent    acoth(expr)
   asech         Inverse hyperbolic secant       asech(expr)
   acsch         Inverse hyperbolic cosecant     acsch(expr)

   Mathematical constants       
   ----------------------
   pi
   e

General tips
------------
* Click anywhere on the graph sheet to plot.

* You don't have to worry about typing expressions in the correct case.
  Everything you type is automatically converted to lower case when you
  plot.

* You don't have to enter multiplication signs everywhere, i.e,
  implicit multiplication is supported. For example, instead of typing
  4*sin(x)*cos(2*x), you can just type 4sin(x)cos(2x). The multipli-
  cation signs will be added automatically.

* You don't have to give brackets at the extreme left or right of an
  expression. For example, you can type sin(cos(tan(x instead of
  sin(cos(tan(x))), and 1+x)2+2x)+3) instead of (((1+x)2+2x)+3). The
  brackets will be added automatically.

* Left-drag the graph sheet to shift the view, instead of changing plot
  settings.

* Right-drag the mouse over the graph sheet and select an area of the
  graph. That area will zoom and fill the entire graph sheet.


                            THAT'S ALL