                           PIECE-WISE GRAFER v3.0
          A program for the TI-85 graphics calculator (Sorry 82s).                             
                             by: David Cantrell
===========================================================================

Readers' Digest Condensed Definition:
***************************************************************************
* PIECE-WISE GRAFER is a program I developed to easily graph a piece-wise *
* function on the TI-85.  Many people will argue with you that the TI-85  *
* cannot graph a piece-wise function or a function within a specific      *
* domain.  I wrote this program to do exactly that.  If you use piece-    *
* wise functions in your math class, then this program is for you.  It    *
* lets you enter the function exactly as it appears in you textbook and   *
* then converts it to the ugly equation that the calculator uses.         *
***************************************************************************

THE INSTRUCTIONS:
~~~~~~~~~~~~~~~~~
Start the program by pressing PRGM+F1+<GRAFPW>.  You can also start it
program by typing GRAFPW at the Home Screen and pressing ENTER.

When the program loads (it may take a long time the first time it is run
because the calculator must tokenize the program file) it will display the
main menu.  You have these options:

	1: Graph Piece-Wise Function
	2: Help
	3: About

Choice 2 displays the online help screen and choice 3 displays the About
screen.

At the help screen use the menu bar to navigate between the three help
screens.  You can press F5 at any of the help screens to return to the
main menu.

Choice 1 will start the piece-wise function graphing procedure.  The first
item the program needs is the number of pieces in the function.  You may
graph a piece-wise function that contains up to TEN pieces.  Simply type
the number of pieces and press ENTER.  If you enter too many or too few,
the program will ask you to re-enter the number of pieces.

After you enter the number of pieces, the program will begin to ask you
each piece and its domain in order.  It will display "Entering Piece #x"
at the top, where "x" is the piece number you are entering.  Type your
expression like you would in the Y(X) or SOLVER modules.  Be sure to use
x-VAR for your x variable or else the program will not generate valid
equations.

When you enter the domain, it first asks you what type of domain it is.
The program defines these two types below:

	1:  Single
	     (i.e. x>2 or x=2)
	2:  Double
	     (i.e. -2<x<2)

Choose the type that matches how your domain is set up.

If you are entering a SINGLE domain:

    The program displays "Entering Domain #x" at the top.  Below it
    displays a single letter "x" with a menu at the bottom containing
    test symbols.  Choose the one that is in your domain.  After you
    choose the symbol, you will see a blinking cursor after the symbol
    you chose.  Type the value that is used in your domain.  Now press
    ENTER and the program displays "Generating piece equation..." at
    the top of the screen.  After this, you will continue on to entering
	the rest of the pieces until all are entered.

If you are entering a DOUBLE domain:

    The program displays "Entering Domain #x" at the top.  Below it
    displays a blinking cursor.  Enter the lowest domain value.  Press
    ENTER and you get a menu of test symbols.  Choose the appropriate
    one.  Now the program displays a "x" and asks for the next test
    symbol.  After you choose the symbol, another blinking cursor is
    displayed.  Enter the highest domain value.  Press ENTER and the
    program displays "Generating piece equation..." at the top of the
    screen.  After this, you will continue on to entering the rest of the
    pieces until all are entered.

After all pieces are entered, you are given a menu of zoom options.  Simply
select a pre-defined zoom window or choose "Custom..." to set the xMin,
xMax, yMin, and yMax to custom values.

After setting the zoom, the program displays the graph of the piece-wise
function.  After it displays the graph, you are given a menu at the
bottom of the screen.  Choose F1 to choose another Zoom option.  Choose
F2 to manually set the Range variables (same as Zoom, Custom...).
Choose F3 to execute Trace mode on the piece-wise function.  If you are
in Trace mode, simply press ENTER to return to the graph menu.  

F4 will let you edit any piece of the piece-wise function you entered.
It will ask you for the piece number and then you enter the piece again
just as you did in the beginning of the program.

Choose F5 at the graph menu to return to the main menu.

When you exit the program, your equations are left in the y(x)=
variables.  You can go back to the graph and perform other operations
(such as EVAL) on the piece-wise function.

While the program is running, all y(x)= equations are disabled.  Only
the ones needed for the piece-wise function are used.  IMPORTANT:  The
program overwrites the equations in y1 through y10 depending on how many
pieces you have.  One Y equation is used per piece.

That's it.  To see the nasty mess of equations that the program generated,
just look at the y(x) equations under GRAPH.

THE OTHER STUFF:
~~~~~~~~~~~~~~~~
If you have any questions about this program or any suggestions, feel
free to contact me.  I can be reached at the following locations:

    http://www.geocities.com/SiliconValley/7938       World-Wide Web
    770-925-8465                                      Phone

PIECE-WISE GRAFER is my work.  I came up with the idea and spent many
hours writing it for the TI-85.  I do not mind if you use the program, 
but please do not modify/change it in any way.

-David Cantrell
 Author of PIECE-WISE GRAFER
 AP Calculus AB
 Brookwood 1996
