Equation Library
04-02-2015, 02:20 AM (This post was last modified: 04-02-2015 02:23 AM by Eddie W. Shore.)
Post: #1
 Eddie W. Shore Senior Member Posts: 1,581 Joined: Dec 2013
Equation Library
The program eqnlib offers 47 equations for HP Prime’s Solver App. Just run the eqlib program, select the category that you are interested in, and select the equation within that category and you are off and running!

Categories include:
* Geometry (areas, volumes, surface areas)
* Finance (monthly loans, sales tax, break-even)
* Temperature Conversion (Fahrenheit to and from Celsius)
* Physics: Problems of Motion (linear distance, circular motion, pendulums, terminal & escape velocity)
* Sound (speed of sound, Doppler effect, loudness)
* Optics (Lens and Snell equations, spherical refraction)
* Electronics (2 resistors series and parallel, thermal noise, Ohm's Law)
* Astronomy (parallax, luminosity, Kepler's 3rd Law, time dilation)
* Great Circle Calculations
* Angle of Incidence Calculations
* Gases (Ideal and Boyle's Gas Laws, heat capacity, air density, isothermal expansion)
* Fluids (depth pressure, fluid flow, Bernoulli's Equation)

When calling each equation, a screen will show each of the variables used, and if necessary, what units you will need to use. While SI (meters, kilograms, seconds) units are used, some equations call for the temperature to be in Celsius, while others require the temperature to be in Kelvin.

The PDF document will list the equations available and the variables used. For eqlib, the global variables A-Z and theta are used.
04-02-2015, 01:37 PM (This post was last modified: 04-02-2015 01:39 PM by salvomic.)
Post: #2
 salvomic Senior Member Posts: 1,396 Joined: Jan 2015
RE: Equation Library
wonderfull!
thank you, Eddie.

But please, control for a little typo in Electronics:

//7.3 2 REsistors: Parallel
should be
IF d==3 THEN (not 2)

Salvo

∫aL√0mic (IT9CLU) :: HP Prime 50g 41CX 71b 42s 39s 35s 12C 15C - DM42, DM41X - WP34s Prime Soft. Lib
04-02-2015, 06:52 PM
Post: #3
 John Colvin Member Posts: 173 Joined: Dec 2013
RE: Equation Library
Nice work Eddie. But I have encountered one problem with this program. When I
attempt to run it from the command line in Home (RPN) it crashes the Prime after I make my selection from the menu. This occurs both in the emulator and the real Prime.
It works fine when running from the Programs Catalog. It would be nice to have the result of Solve placed on the RPN stack.
04-03-2015, 03:42 AM
Post: #4
 ebswift Junior Member Posts: 28 Joined: Apr 2015
RE: Equation Library
Thanks Eddie, this is very nice, very useful. My first downloaded program .
04-05-2015, 10:40 PM
Post: #5
 akmon Member Posts: 199 Joined: Jun 2014
RE: Equation Library
Thank you for the library. It´s very cool.
05-21-2015, 11:22 PM
Post: #6
 akmon Member Posts: 199 Joined: Jun 2014
RE: Equation Library
Don´t know how to program it, but if you have checked another equation (E2, E3...) in solve app, the program does not work well. The issue is automatically uncheck all the equations you have in solve app previously.
06-17-2015, 07:44 PM
Post: #7
 Nepomuceno Junior Member Posts: 1 Joined: Jun 2015
RE: Equation Library
First of all, thanks for sharing .
I've had success with the Library on my emulator , but the HP Prime could not.
Syntax error message on line 10. Does anyone know why ?
Thank you.
06-18-2015, 06:11 AM
Post: #8
 Didier Lachieze Senior Member Posts: 1,630 Joined: Dec 2013
RE: Equation Library
(06-17-2015 07:44 PM)Nepomuceno Wrote:  I've had success with the Library on my emulator , but the HP Prime could not.
Syntax error message on line 10. Does anyone know why ?

You may have an error if you have set the comma as the decimal separator on your HP Prime.
To fix this issue you need to add a pragma statement as the first line of the program:
Code:
#pragma mode( separator(.,;) integer(h32) )

This pragma says to the parser that no matter YOUR Home Settings, the program follow the syntax:
decimal separator is a point in the program.
parameter separator is a comma in the program.
command separator is a semi in the program.
and integers are 32 bits hexadecimal

You can find more details here.

A comment for people posting HP Prime programs: it is a good practice to start any program with a #pragma statement. It avoids troubles if you change your decimal separator later on or if you share your program with someone using different settings.
06-30-2015, 07:56 PM
Post: #9
 rgallier Junior Member Posts: 27 Joined: Feb 2015
RE: Equation Library
This is something that I think should be delivered as part of the base software. I would love to see this run from the soft key between "=" and "Show" and have it put the chosen equation in the currently selected equation field. It would be great if it could pull the menu, equations, and variable descriptions from a sister spreadsheet or data file with and editor.
07-11-2015, 05:56 PM
Post: #10
 rgallier Junior Member Posts: 27 Joined: Feb 2015
RE: Equation Library
Choosing the currently selected didn't seem a likely possibility because this position value does not appear to be retained. I've looked at how to determine the next available E# = 0 and use this to store the selected equation without success. If 0-9 are all 0 this would require the user to delete an equation.
05-12-2017, 10:33 AM
Post: #11
 coitboy2000 Member Posts: 104 Joined: May 2017
RE: Equation Library
Very useful, thanks.

Is there any way to return back to the start of the program by capturing the Escape Key? i.e. Can you exit the solver app but return control back to the calling program and let the user exit via an option from a message box?
05-13-2017, 08:51 AM
Post: #12
 Gamo Senior Member Posts: 734 Joined: Dec 2016
RE: Equation Library
How to transfer file to HP Prime for Andriod?
05-13-2017, 03:47 PM
Post: #13
 compsystems Senior Member Posts: 1,363 Joined: Dec 2013
RE: Equation Library

01-21-2024, 03:19 PM
Post: #14
 Primer of the HP Junior Member Posts: 1 Joined: Jan 2024
RE: Equation Library
This is an inactive and multiple year old thread but hey:

I am consistently getting a syntax error on line 594 despite wiping my calculator several times.
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