EQL  :  A user equation library                 Version 3.2

---



EQL is a user maintainable equation library. It allows you to keep 

track of your functions in a tidy and efficient way, using a full 

screen chooser environment. It is reminiscent of the built in equation 

library in the G/GX, but works on the S/SX too.



EQL lets you:

 - store equations that you use often

 - store text and view in regular or compressed font

 - store pictures

 - run programs 



All this is available from a fast, full screen CHOOSE environment. 

If you want JUST the fast chooser, try out the subset library, 

FCS.LIB, which is about half the size of EQL.LIB.  (FCS is FCHOOSE.ZIP on

Goodies Disk 10)



Matt Willis

10 December 1995





VERSION

-------

3.0 	Faster Scrolling (ml), minor bugfixes

3.1	Supports ram cards as source for EQDIR

3.2	Library put on a diet (lost 400 bytes through rewrites)

	Now "browsing" is better (can enter and exit the eqn viewer)



COMPATIBILITY

-------------

   EQL is 99% SysRPL, 1% ML and is compiled for the G/GX. I am not aware 

   of any unsupported entry points that I may have used.



   So it *should* work on an S/SX too. 



TO INSTALL

----------

Library file: EQL32b.LIB



Download library file to calculator. Recall the library to the stack. 

Type 0 STO (or another number if you have more ports). Turn calculator off, 

then on. Delete original copy of library (since a copy is now in port 

0). It's installed.



OVERVIEW

--------

The basis of the library is that it looks for functions stored in a 

directory called EQDIR. 



1. From now on, store your equations in a subdirectory called EQDIR. 

Give them creative names, such as 'BatchReactorDesign'. The EQL library

shows the first 20 letters of any name.



2. Run EQLIB, and, assuming the current directory contains the 

subdirectory EQDIR, you'll be given a list of equations to choose from. 



3. When you choose one, you can look at the item (or, if it's a list, 

the items). Press the right and left arrow keys to move forward or 

backward.



4. Press SOLVR to enter the SOLVER, ->STK to put the equation on the 

stack or CANCL to choose another equation.



FAST START

----------

If you already have a lot of equations, create a subdirectory called EQDIR :

  'EQDIR' CRDIR

and then move your equations into this subdirectory (perhaps using the memory

tool in the G/GX)



Make sure you are in the directory ABOVE the directory EQDIR and then type

  EQLIB





FEATURES

--------

From now on, you should try to put your equations in lists. You don't 

have to, but if you do, you can take advantage of some of the neater 

features of EQLIB.



You can put help text into lists, alongside equations. You don't even 

need to put any equations at all. (You can make a multi-page help file 

this way.) You can also put GROBS in a list. That means you can have a 

lot of supporting material along with an equation.



If you put a program in EQDIR, it will be executed, unless it is an 

algebraic like << -> a << a 1 + >> >>. So if you've created programs 

that don't need anything from the stack, you can easily put them in 

EQDIR as well.



Generally, when you select an object this is what happens...



  selected object    action

  ---------------    -------------------

  grob|text          view item, then quit

  {list}             view items in list, put on stack or

                     enter the solver

  'equation'         view item, then quit or enter the solver

  Mpar library data  Store in Mpar, then execute MSOLVR

  <<program>>        Execute, or if algebraic, view.

  other              view item, then quit

  



NEW COMMANDS

------------

The following is a list of new commands your HP will have. Unless you 

like to program, all you'll need will be the EQLIB command. If you 

don't understand what all these commands are for, don't fret.



ABOUT   (->)  

        "About" information for this library



FCHOOSE ($ {list} number -> object 1 | 0)

        A full screen replacement for the G/GX CHOOSE command. 

        Same syntax. Should work on an S/SX!



TITLE   ($ ->)

        Show a nice title (centered) on the top of the screen.

        Mimics #E0044h LIBEVAL on the G/GX.



EQLIB   (->)

        Start the equation library. (Main command)



PCHOOSE ($ {list}-> number 1 | 0)

        Similar to the CHOOSE command, except it goes full page by full 

        page.



TITLE2  ($ $ ->)

        Show a nice title (left and right justified) on top of screen.





Some examples follow in the next section, "Tips and Tricks"



TIPS AND TRICKS

---------------

1) Making EQLIB easy to get at



Create a custom menu. I swear by them. Every working directory I use 

has a custom menu. When you're in the directory ABOVE EQDIR, type in 

the following:

      { EQLIB EQ { "SOLVR" << 30 MENU >> } {} {} EQDIR } MENU



This creates a variable CST which you can see if you press the CST key!



2) Using the built-in MES solver:



By default, the EQLIB uses the regular solver. 



To use the built in MES solver you can create an Mpar variable and then 

save it under a different name in EQDIR. Or, you can use a program to 

set up the multiple equation solver, like: 



<< { 'X=r*COS(theta)' 'Y=r*SIN(theta)' }                                        

    STEQ                                                                        

    MINIT                                                                       

   "CIRCLE STUFF"                                                               

    { X Y "" r theta }                                                          

    MITM                                                                        

    MSOLVR                                                                      

>>



Note that this approach can let you store values in variables as well. 

I personally do not like "pre-seeding" variables, but you are welcome 

to do so. When this program is executed, it will be in the directory 

_ABOVE_ EQDIR.





3) Making a help file (with pages of text, but no equations)



I don't think you should be cheating on exams with your HP. It's more 

of a common sense thing, as far as I am concerned. But you can create 

pages and pages of text, and display it in a really crammed in format. 

You'll have to tell the program where the newlines go, but that's easy 

enough.



e.g. Normal font: (selected when your text has < 6 lines )

'HELPTEXT'

{ 

"This is a page

of regular text"

"This is the

second page of

regular text"

}





e.g. Condensed font: (selected when your text has more than 6 lines)

{

"This is a page of crammed

text and you can fit a lot

of text on one screen. Just

remember that you have to 

put at least 7 or 8 lines of

text for EQLIB to know that

you want condensed text."

"This is big font"

}





4) Using a descriptive name



You can create "illegal" names for your EQDIR that include spaces and 

other characters by using a SYSEVAL, ($>ID). This syseval is supported 

so it should work equally well on an S/SX and G/GX.



Example:

   { object }

   "Illegal Name" #05B15h SYSEVAL STO



WARNING: Type this in wrong and your memory can be erased!!



To erase something with an "illegal" name, go through the above 

procedure again:

   "Illegal Name" #05B15h SYSEVAL PURGE





5) Including help information with your equations



Create a list with your equations in it. As an item in the list, 

include a multi-line string that explains a little about the funtions.



e.g. 



{

"CIRCLE FORMULAE

Cartesian space

r=radius"

'x^2+y^2=r^2'

}



Before you enter the SOLVER, the text will be stripped out. Same goes 

for GROBS.







6) Using the other commands in the library



I included them because I thought maybe 5% of the users might like 

them. Don't worry about them if you can't see what they're for. You can 

safely ignore them. 



The TITLE and TITLE2 routines put pretty titles on the top of the 

screen:



<< CLLCD "HELLO WORLD" TITLE 1 FREEZE >>

<< CLLCD "HELLO" "WORLD" TITLE2 1 FREEZE >>



The ABOUT command tells you about the software version.



The FCHOOSE command replaces the CHOOSE command in the G/GX. The syntax 

is identical to that found in the Advanced User's Reference. Try the 

following:



<< "TITLE" 

  { "ITEM 1" 

    { "ITEM 2" "SURPRISE"}

    3.14159

  }

  1     @ start row for menu bar

  IF FCHOOSE THEN 1 DISP 1 FREEZE END

>>





7) How to store your equation library on a memory card:



Once you have a directory up and running (and are unlikely to be making

changes on a daily basis) you can store it in a port. This frees up some

of your HP's main memory. Tell EQL where to find the directory by 

putting the name of the port object in a list, and storing this in the 

variable EQDIR. The whole process might go like this:



  'EQDIR' RCL

  :1:'SampEqns' STO

  'EQDIR' PGDIR

  { :1:'SampEqns' } 'EQDIR' STO