11-04-2017, 01:30 AM

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:

Thanks!

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!