Calling a CAS function in a program
11-04-2017, 01:30 AM (This post was last modified: 11-04-2017 08:26 PM by eulus.)
Post: #1
 eulus Junior Member Posts: 1 Joined: Nov 2017
Calling a CAS function in a program
Hi,

I'm trying to write an HP program that numerically solves a system of nonlinear equations using the CAS function fsolve, with certain parameters depending on local variables (inputs). I get an "Error: Bad Argument Value" when trying to run the program, despite the same system getting solved just fine when I type it into CAS. The only thing I could find online was this post, where they discussed issues with using local variables in CAS functions, but nothing definitive was reached. Here's my code for reference:

Code:
 EXPORT exponential_model() BEGIN   LOCAL V, R, Vr, Ir, n, Vt; // inputs   LOCAL Is, Vd, Id; // outputs being solved for   INPUT( {V, R, Vr, Ir, n, Vt},     "Enter parameters", {},     {"Voltage source", "Resistor", "Reference voltage", "Reference current", "Empirical constant", "Thermal voltage"} );     RETURN CAS.fsolve({Ir=Is*(e^((Vr)/(n*Vt))-1),Id=(V-Vd)/R,Id=Is*(e^((Vd)/(n*Vt))-1)},{Vd,Id,Is}); END;

Thanks!
11-04-2017, 04:41 PM
Post: #2
 parisse Senior Member Posts: 911 Joined: Dec 2013
RE: Calling a CAS function in a program
I don't think you can use Home local variables as unknowns for fsolve. Make a CAS program and use CAS global variables (or CAS local variables and purge them).
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