ExprCalc 1.0    (5/3/2000)
==========================

My English is very bad, if you understand Czech language,
you can read original in CTIME.TXT.

Program runs on TI-89 and maybe on TI-92. It's for fast
calculating expressions with different values. It's very
useful when you want calc more expressions with more values...

How to install it
+++++++++++++++++
Send file EXPRCALC.89P by something to your TI-89 to some folder.
I can recommend you to send it to MAIN. Name of the file is
kbdprgm2 so you can run it easily by "diamond" + "2"
You can archive it but I recommen you to run it once
before it (it will be faster).

Examples how to use my program
++++++++++++++++++++++++++++++
Example 1|    - Easy expr., storing values, ':'
----------
Run it ("diamond" + "2")
Enter expression. For example 2(a+b). I can recommend you to
put in to clipboard by "COPY", it's useful when you want
later put similar expr., you don't need to write it all again.
Press "ENTER"
Now write values of variables (a=3 and b=5)
It shows " 16"
You can try another values...
If you want to go back to entering new expr., instead a value
press only "ENTER"
Now PASTE old expression and add "->o", where "->" means "STO ->",
whole expr. is now 2(a+b)->o  (you can use also COPY).
Enter values 3 and 5, it shows " o=16". Cool, isn't it?
Go to entering expr. and add ":o+3->o2",
whole expr. is 2(a+b)->o:o+3->o2
Let's try some values... You can quit program if you instead
an expression press only "ENTER"

Example 2|    - Calculating with units
----------
Try  1/2_g*(t*_s)^2->s

Example 3|    - functions and greek chars
----------
sin(alfa)->x:sin^-1(x)->beta:2*pi*r
(sin^-1  is "diamond" + "Y"
instead of alfa, beta, pi (pi is constant, others are variables)
use greek chars

Example 4|    - example from school
----------
Missile flies from tower (30m high) - start angle is 60 degrees and
speed is 10 m/s. Make a table for time 0, 1, 2, 3, 3.5 and 4 seconds,
where will be position in X and Y, horizontal speed, vertical speed,
total speed, potencial energy, kinetic energy and total energy.
Missile is 3kg heavy. g = 10 m*s^-2

=> x0=0, y0=30, alfa=60, v0=10, m=3

our formulas:
x = v0*t*cos(alfa)+x0
y = -1/2*g*t^2+v0*t*sin(alfa)+y0
vx = v0*cos(alfa)
vy = v0*sin(alfa)-g*t
v = sqrt(vx^2 + vy^2)       - sqrt is "2nd" + "*"
Ep = m*g*y
Ek = 1/2*m*v^2
E  = Ep+Ek

- with normal calculator (or TI-89 without ExprCalc) it's lot
of work...

But we have got ExprCalc and so we can type (don't forget what
alfa and sqrt means and use mode in degrees):
10t*cos(60)->x:-5*t^2+10t*sin(60)+30->y:10*cos(60)->vx:
10*sin(60)-10t->vy:sqrt(vx^2+vy^2)->v:30y->Ep:1.5v^2->Ek:Ep+Ek->E

-type it carefully (Ep isn't ep or eP)
You can put it to the clipboard by COPY.
Now you can enter time and you can write results...

Example 5|    - Quadratic formula
----------
try
b^2-4a*c->D:(-b+sqrt(D))/2a->x1:(-b-sqrt(D))/2a->x2

(do you know what "->" and "sqrt" mean? :)



Recapitulation
--------------
You can use as much as 100 variables (you can change it in
source code). You can use ":" for more expressions, you can
store variables, you can use functions (like sin, cos...),
units.
!!! Variables are only fictive, they aren't in some folder...
!!! Variables are in entering expression case-sensitive
!!! but in calculation isn't (try a+A  and a=5, A=8 - you will
!!! get undef)

If you don't like using COPY to put it into clipboard, you can
change it on the top of source code by setting req_ - try it -
it store last expression but it use small chars...

If you type something like 1+2 (it doesn't stop), you must use
"ON"

At the end...
-------------
This programme is very useful, i wanted to program it because
my borther's calc CASIO FX 880p has cool key CALC and I haven't
found something similar on TI-89...
I hope you will enjoy it.

Bugs
----
I think it hasn't bug (except my English :o). If you find
someone, mail me...

Suggestions
-----------
If you have someone, mail me...

Warranty
--------
!!! no warranty !!!

My e-mail and my name
---------------------
TOMAS BORIL   from Czech Republic
borilt@email.cz

You can write me also if you find this programme useful,
I will be very happy if you send me some e-mail ;-)






