```Date: May 8, 2013 10:42 AM
Author: Torsten
Subject: Re: complicated equation including bessel functions

"ghasem " <shaban_sadeghi@yahoo.com> wrote in message <kmdndp\$6\$1@newscl01ah.mathworks.com>...> > You solve in _two_ unknowns: bet_real and bet_imag.> > You evaluate your bessel functions for z=bet_real+1j*bet_imag.> > You return the real and imaginary part of exp1(i) to fsolve.> > (Two equations in two unknowns).> > > > Best wishes> > Torsten.> ===========================> thank you Torsten.but your suggestion is not good.> because,when in complex algebra in matlab,you use from real and imag commands,you only increase complexity of your problem.because,your complex unknown is within bessel argument,yet.> for example,look at this code:> syms a b   % a,b real> c = a+1j*b;> d = besseli(1,c);> real(d)> ans=> conj(besseli(1, a + b*i))/2 + besseli(1, a + b*i)/2> imag(d)> ans => (conj(besseli(1, a + b*i))*i)/2 - (besseli(1, a + b*i)*i)/2> % so,you can see,when your problem is big,when you use from real and imag command,only your equation become longer.> also,I tested my equation with simple fzero (without separate real and imag parts)and with your suggestion.> I saw that my answers in first case,was correct and in latter case,was false.> i.e IN MATLAB SOFTWARE,there is not any method for complicated equations including bessel functions with comlex argument????> best wishes> ghasemThe method I suggested is a method that will work with fsolve.Since fsolve does not work with symbolic variables, I don't see that anything gets more complicated using the above approach.I doubt that fzero works with complex numbers since it is based on a dissection method that does not work in the complex plane.Best wishesTorsten.
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