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Topic: complicated equation including bessel functions
Replies: 22   Last Post: May 8, 2013 2:43 PM

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 ghasem Posts: 118 Registered: 4/13/13
Re: complicated equation including bessel functions
Posted: May 8, 2013 2:18 PM

> See above about FSOLVE versus SOLVE. Either keep all your calculations
> symbolic or keep all your calculations numeric. Mixing the two requires
>
> --
> Steve Lord
> slord@mathworks.com
> http://www.mathworks.com

=============================
No,i know that fslove and fzeros are for numeric calculations.
in fact,I use from syms,so that I can define a parameter in intermediate parameters.see my code,please:
syms bet % bet is my unknown
for i = 1: 100
% eps1 , k1,k2,k0 are known complex constant.
gam = sqrt(bet^2 - k1^2);
T = sqrt(bet^2 - k2^2);
tau = sqrt(bet^2 - k0^2);
%
X1 = gam*besseli(0,gam);
X2 = T*(eps1*besseli(1,gam)-(1-eps1)*gam.*besseli(0,gam));

X3 = -T*tau*bessely(0,T)*besselk(1,tau)-...
tau^2*bessely(1,T)*besselk(0,tau);
X4 = -T*tau*besselj(0,T)*besselk(1,tau)-...
tau^2*besselj(1,T)*besselk(0,tau);

exp1(i) = X1.*(besselj(1,T).*X3 - bessely(1,T).*X4)-...
X2.*(besselj(0,T).*X3 - bessely(0,T).*X4);

my_guess = (i/100) +1j*(k0+(i/m));
exp2(i) = fsolve(@(bet)eval(exp1(i)),my_guess);

real_ans(i) = real(exp2(i));
imag_ans(i)= imag(exp2(i));
end
%
I used from fsolve for syms variable with " fsolve(@(bet)eval(exp1(i)),my_guess)"
by this command,you can use from fsolve,when your unknown is defined as symbolic.
this is not my problem.
my problem is that how solve "exp1" in the above?because my arguments in bessel functions are complex.
ghasem

Date Subject Author
5/7/13 ghasem
5/8/13 ghasem
5/8/13 Torsten
5/8/13 Bruno Luong
5/8/13 Torsten
5/8/13 ghasem
5/8/13 Bruno Luong
5/8/13 ghasem
5/8/13 Nasser Abbasi
5/8/13 Bruno Luong
5/8/13 ghasem
5/8/13 Torsten
5/8/13 ghasem
5/8/13 Torsten
5/8/13 Bruno Luong
5/8/13 ghasem
5/8/13 Bruno Luong
5/8/13 ghasem
5/8/13 Steven Lord
5/8/13 ghasem
5/8/13 Steven Lord
5/8/13 ghasem
5/8/13 ghasem