Collection of Tools & Utilities/Collection of Tools and Utilities.iso/graphic/grafit20.zip/README

Text File | 1993-01-14 | 12KB | 207 lines

+--- +--- | /************  GRAF-IT! v2.0 -- README  ************+--- +--- | /
|--  |--  K********************  January 1993  *****************|--  |--  K
+--- +--- | \******  (c) Copyright 1990 Eugene Eric Kim  *******+--- +--- | \

WHAT GRAF-IT IS?
     GRAF-IT! v2.0 plots functions and inequalities of functions, as well as
solves systems of inequalities.  It is a very intuitive, yet powerful math
graphing program.
     This was written as an educational tool for the math department at
Polytechnic Upper School in Pasadena, CA.  It is appropriate for junior high
school, high school, and college students.

WHY GRAF-IT?
     There is an abundance of graphing software available, both shareware and
commercial.  Some packages are extremely powerful, yet their interfaces tend
to intimidate the average user.  Other packages are extremely simple (and
often free), yet their usefulness is limited to drawing lines and circles.
     GRAF-IT! can be classified as a simple package, yet its power goes
beyond other "simple" packages.  It plots a plethora of functions, and allows
almost complete manipulation of the graph range.  It maintains a buffer of
seven equations, so you can keep track of what you're doing, as well as save
the last seven equations you typed and the range.  The user interface is
extremely intuitive -- you just type in the equation and press return.
     The most powerful feature of all, the reason GRAF-IT! was written, is
the inequality feature.  Systems of inequalities are used in many real-world
applications, from construction to economics.  Very few programs have this
ability, and those that do are generally anti-intuitive.  GRAF-IT! will not
only graph inequalities of functions, it will graph the solution to a system
of inequalities with a one key command.
     A combination of all these features makes GRAF-IT! a powerful tool,
especially for building intuition.  It was written to be an education tool,
and can be used to help students understand algebraic concepts such as
solutions to systems and even simple calculus concepts such as maximums and
minimums.  For those students beyond this level, GRAF-IT! can be used to
analyze scientific and technical problems.

GETTING STARTED:
     The only hardware requirement for GRAF-IT! is a VGA monitor.  It will
work equally well on an XT machine as it will on a 486 machine.  In fact, it
was written on a Leading Edge Model D, an Intel 8088 based machine.
     There is only one necessary file: GRAFIT20.EXE.  The archived package
should include the following files:
           GRAFIT20.EXE -- GRAF-IT! v2.0 executable
              DEMO1.EGC -- Demo files
              DEMO2.EGC
              DEMO3.EGC
                 README -- This readme file
     Just type GRAFIT20 at the DOS prompt and you are ready to begin.  There
are two command line options:

           GRAFIT20 [notitle] [load:{filename w/o extension}]

The 'notitle' option prevents the opening screen from displaying.  The
'load:' option allows you to immediately load a file.  Just type the filename
of the .EGC file WITHOUT extension and with no space between the colon and
the filename to load the file.

USING GRAF-IT! v2.0
     GRAF-IT! operates on a command line principle.  All commands and
functions are typed in the box labelled, f(x).  Every command is one letter.
In order to execute a command, type the letter and press <RETURN>, then
follow the instructions.
     In order to graph a function, just type the function in and press
<RETURN>.  A couple of notes on functions: first, there are certain letters
which are not allowed -- if you press an invalid key such as <SPACE>, you
will hear a beep, and the character will not appear.  Also, make sure each
argument inside a function is surrounded by parentheses.
     If the buffer is on (default), all equations are queued into the
buffer.  To toggle the buffer off, just type T (see the section COMMANDS),
and the equations will no longer be queued.

COMMANDS
     L -- Load file: Loads up previously saved equations and range values.
Enter the file name without the extension at the prompt.
     G -- Save file: Saves the current set of equations as well as the
current range values.  Enter the file name at the prompt.  Will automatically
add the .EGC extension.
     C -- Clear the graph: Clears the graph.  Does not reset any values.
     I -- Inequality mode: Allows the user to enter inequalities.  At the
prompt, choose which inequality you want.
     S -- Solve system: Solves a system of inequalities.  There must be two
or more inequalities in the buffer.  The S command will redraw the graphs and
fill in the solution, if there is one.  If there is not, the program will
notify you.
     V -- Vertical line: Lets you plot vertical lines.  Enter a number at the
prompt (x=?).  In order to enter an inequality of a vertical line, use the I
command first, then V.
     W -- Redraw: Allows you to redraw equations that are in the buffer.  The
command prompts you either for the number of the equation, or A for all, or C
for cancel.
     F -- Replace sign: Lets you change the sign in an equation in the
buffer.  First select the equation (or C for cancel), then the sign.
     Z -- Display equation: For especially long equations, the buffer will
truncate the expression.  In order to see the whole equation, use this
command.
     A -- Add equation: This command lets you put equations into the buffer
without graphing them.  This is a useful command for demonstration purposes,
as well as speed (if you are using 8088 machines).
     T -- Toggle buffer: Turns the buffer queue on and off.  The default is
on.
     P -- Purge buffer: Delete all of the equations in the buffer in one fell
swoop.  Be careful with this command; once you use it, your information is
gone forever!
     R -- Set range: Let's you set the range of the graph.  This can be used
as a zoom function -- change the range, then redraw the equations.
Limitations of the zoom function: the tic value cannot be set; only integer
values can be entered.
     E -- Reset graph: Clears the graph and restores the default range
values.  (X and Y Min = -10, X and Y Max = 10).
     D -- Delete from memory: Allows you to delete individual equations from
the buffer.
     H -- Help.  The help is not too bad, but it is a little uncomfortable to
use.
     Q -- Quit.  Self-explanatory.

FUNCTIONS
     The following are all legal functions and operations:
           +   -   *   /   (   )   ^   sqrt   log   ln   exp   sin
           cos   tan   sec   csc   arcsin   arccos   arctan
Remember to keep the arguments inside of the functions surrounded by
parentheses.
     There is one limitation with the power (^) function.  See the reference
to error message #5 in the section on ERROR MESSAGES below.

ERROR MESSAGES
     #1 -- Illegal Input Error: The user entered a garbled message.  If you
enter some unknown function, this error will appear.
     #2 -- Missing Constant or Variable Error: If there are no numbers or
variables in the expression the user has typed, this error will occur.
     #3 -- Missing Parentheses Error: The parser checks to make sure there is
a corresponding end parenthesis for every open parenthesis.
     #4 -- Dangling Operator Error: If there is a binary operator with only
one element, this error is displayed.  (ie. f(x)=+X+1)
     #5 -- Fractional Power Error: Because of a weakness in my parser, if you
are entering a fractional power expression, it must be in the following form:
           ^({numerator}/{denominator})...
You CANNOT have any expression preceding the numerator or the end
parenthesis.  The following is an illegal expression:
           X^(1/3+1)
There is a flaw in my parser which is the reason for this.  If you are
interested in why this does not work, please send e-mail or write, and I will
be happy to explain.

HISTORY
     In my sophomore year, my math teacher approached me and asked me to
write some software for