Calling a CAS function in a program - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: HP Prime (/forum-5.html) +--- Thread: Calling a CAS function in a program (/thread-9435.html) Calling a CAS function in a program - eulus - 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: 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! RE: Calling a CAS function in a program - parisse - 11-04-2017 04:41 PM 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).