Problem in contour plot using ''for '' loop.

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AVM
AVM on 24 Jun 2020
Commented: KSSV on 24 Jun 2020
I would like to get a contour plot in the following code, but some prolem is occuring. Please somebody help me to solve that.
clc;
syms t g
n=6;
I1=eye(n);
I2=eye(2);
matdimension= n-1;
tempvector = 0:1:matdimension;
tempvector = sqrt(tempvector);
tempmatrix = diag(tempvector);
anni= circshift(tempmatrix,-1);
crea = anni';
num=crea*anni;
c=crea+anni;
sigx=[0,1;1,0];
t=0:0.01:1;
g=0.0001:0.01:0.49;
M= zeros(size(t));
for i = 1:length(t)
for k=1:length(g)
A= g(k).*kron(I2,num)+ t(i)*kron(sigx,c);
[~,v]=eig(A);
M(i)=v(2,2);
[T,G]=meshgrid(t,g); %%%%%%%%%% upto this line it is working......
F=M(T,G); %%%%%% for here the problem is starting.
end
end
contourf(T,G,F)
colormap(cool)
%%%%%%%%%%%%%%output error
Index in position 1 is invalid. Array indices must be positive integers or logical values.
Error in tial (line 35)
F=M(T,G);
  2 Comments
KSSV
KSSV on 24 Jun 2020
What is the purpose of this?
F=M(T,G); %%%%%% for here the problem is starting
Offcourse, it will give error...
AVM
AVM on 24 Jun 2020
Edited: AVM on 24 Jun 2020
Actually I need to see how the contour plot looks like in this case and I have to compare it with other system of equations.

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Answers (1)

KSSV
KSSV on 24 Jun 2020
May be you are looking for
contour(T,G,M)
  2 Comments
AVM
AVM on 24 Jun 2020
Actually by anyway I need to plot that contour (t,g,m). I thought that some meshgrid has to be assigned first within the for loop and define M as M(T,G). But it is not woking. Please, help me to get that. I do this using foor loop because the eigenvalue calculation is taking long time symbolically. It will take even more time if I increase the dim. of the matirx A.
KSSV
KSSV on 24 Jun 2020
There is no need to use syms...you can remove it.

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