GTEXT is an abbreviation for "graph text".  The program allows the user
to add text or arrows to any graphical display.


GTEXT.85P was written by Pat Milheron of the TI Graphics Team and is
released to the public domain.  You may copy and change this program.

INTRODUCTION

Many teachers around the country want a way of annotating graphs for
incorporation into a document via an .EPS or .TIF file.  GTEXT is an
abbreviation for "graph text".  The program allows the user to add text or
arrows to any graphical display.

HOW TO USE GTEXT

GTEXT works in any of the graph modes with any RANGE settings. Enter any
equations in the graph equation editor that you want to overlay text onto.
You can either graph it before running GTEXT or let the program graph it
for you.  The program (using "Smart Graph") will display a graph 
automatically at the start of execution.

Once the graph has been drawn, the main menu for GTEXT is displayed:

     -----------------------------------
    | QUIT |     | GRAPH | ARROW | TEXT |
     -----------------------------------

The general flow to using the program is:

1) Position the cursor using the GRAPH option from GTEXT main menu.
2) Choose either the ARROW or TEXT menu option.
   * If you have chosen ARROW, select the direction from which the arrow
     should point (8 choices).
   * If you have chosen TEXT, enter the text you want to display, followed
     by [ENTER].
3) The graph is updated with either an arrow or the text.
4) You can continue to add text or arrows by returning to step 1.

QUIT   Exits from program and saves graph in the picture variable NEWGRAPH.

       Note: If you use the ON key to "break" out of the program, the graph
       will not be saved in a picture variable.

GRAPH  Puts the graph into the screen with a free-moving cursor at the
       center of the screen.

       Move the cursor to the position on the graph where you want your
       text to start, or where you want the point of an arrow to be
       located.  For text, the cursor location will be the upper left
       location of the text to be written. All text is 5 pixels high and
       up to 5 pixels wide.  A pixel space is inserted between characters.

       Once the cursor location is chosen, press ENTER to "select" the
       location and return to the main menu.

ARROW  Allows you to draw an arrow with the point being located at the
       current cursor position. There are 8 different arrows that can be
       drawn, they differ only by their direction. Select the type of arrow
       from the arrow sub menus:

                           ^       |
                           |       |
         <----   ---->     |       v
        --------------------------------------
       |  LEFT | RIGHT |   UP  | DOWN  | MORE |
        --------------------------------------
                                          ^
                                          |
                                          v
        --------------------------------------
       | 1ST Q | 2ND Q | 3RD Q | 4TH Q | MORE |
        --------------------------------------
           /     \         ^      ^
          /       \       /        \ 
         v         v     /          \

       Note: Q is quadrant from which the arrow points at a 45 degree
       angle; v or ^ is the arrow head.

TEXT   Prompts you for text to be written on top of the graph.

       Text is normally written left to right from the current cursor
       position. Text can be written downward from the current cursor
       position by starting your text with the Greek letter lambda, which
       is located under the CHAR GREEK menu.

       The characters that can be written on the graph are limited in
       number in order to keep the size of this program to a minimum.  Any
       character not in the valid character set will just be skipped over.
       Lowercase letters are output as uppercase except x, y, r, and t.

VALID CHARACTER SET:
  Lowercase alphabet: (only x, y, r, and t are output as lowercase)
  Uppercase alphabet: A-Z
  Space
  Greek letters: theta,pi
  Numbers:  0-9
  Math operators: +  -  *  /  ^ =  negate (-)
  Brackets:  (  )  [  ]  {  }
  Punctuation:  .  ,  '  :
