For loop inside functions in fsolve

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Meva
Meva on 21 Aug 2016
Edited: Qu Cao on 24 Aug 2016
Hello, I have 2 by 2 system of nonlinear equations.
I will use for loop for my time T inside these two functions.
I have this function for fsolve:
function F=torder1(x)
x_1=[0:0.01:1];
b=0.6;
dt = 0.01;
Nt = 1/dt+1;
%$ sol(1) = h; sol(2) =theta;
clear x_1;
syms x_1 h theta kappa
f_1(x_1,h,theta,kappa) = 1/2*(1-( (h+(1-b)*theta)^2/(h+(x_1-b)*theta-kappa*x_1*(1-x_1))^2 ));
f_2(x_1,h,theta,kappa) = (x_1-b)/2*( 1-( (h+(1-b)*theta)^2/(h+(x_1-b)*theta-kappa*x_1*(1-x_1))^2 ));
kappa =1;
f_11 = 1-( (h+(x_1-b)*theta)^2/(h+(x_1-b)*theta-1*x_1*(1-x_1))^2 );
f_21 = (x_1-b)/2*( 1-( (h+(1-b)*theta)^2/(h+(x_1-b)*theta-x_1*(1-x_1))^2 ));
fint_1 = int(f_11, x_1);
fint_2 = int(f_21, x_1);
x_1=1;
upper_1=subs(fint_1);
upper_2=subs(fint_2);
clear x_1;
x_1=0;
lower_1=subs(fint_1);
lower_2=subs(fint_2);
clear x_1;
integral_result_1old=upper_1-lower_1;
integral_result_2old=upper_2-lower_2;
h0 = kappa *b*(1-b);
theta0 = kappa*(1-2*b);
integral_result_1 = subs(integral_result_1old, {h, theta}, {x(1), x(2)});
integral_result_2 = subs(integral_result_2old, {h, theta}, {x(1), x(2)});
*for nt=1:Nt
T(nt)=(nt-1)*dt;
F(nt)* = [double(x(1) - integral_result_1*T(nt)^2 -h0);
double(x(2) - integral_result_2*T(nt)^2 - theta0)];
end
Also I have my script in which the function torder1.m is nested:
x0 = [.1, .1];
options = optimoptions('fsolve','Display','iter');
dt=0.01;
Nt=1/dt+1;
[x,fval] = fsolve(@torder1,x0,options)
h = x(1)
theta = x(2)
I have to loop over my time T (very bottom in the torder1.m function) and in every time step,
I need to get my x(1) = h and x(2) = theta and related F in every time and save them to plot against T.
The time index is shown as nt.
Thanks for any help.

Answers (1)

Qu Cao
Qu Cao on 24 Aug 2016
Edited: Qu Cao on 24 Aug 2016
I recommend you to provide more details about the equations you want to solve.
You can also refer to the following documentation to see how to use 'fsolve':

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