Only storing final for loop values

I am trying to plot t vs I1 and t vs I2, but only the last value of the loop is being stored. I am very new at this so any help would be great

H= [ 0.5*1i -1; -1 -0.5*1i];
psi0= [1; 0]; 
for n= 1:0.01:10
    t=n;
    G= expm(-1i*H*t);
    psi= G*psi0;
    I1= (abs(psi(1,1))).^2;
    I2= (abs(psi(2,1))).^2; 
end 
 plot(t,I1)
 plot(t,I2)

[per isakson]

Did you try to replace

I1= (abs(psi(1,1))).^2;

by

I1(:,n)= (abs(psi(1,1))).^2;

?

Answer 1

[Adam Danz]

You're overwriting the t, I1 & I2 variables on each iteration. At the end of the loop, you're left with only the final values.

Here is a modification of your code so you that can store the values from each loop.

H= [ 0.5*1i -1; -1 -0.5*1i];
psi0= [1; 0];
n = 1:0.01:10;                  % Moved outside of the loop
I1 = nan(1,length(n));          %allocate the loop variable
I2 = I1;                        %allocate the loop variable
for i = 1:length(n)             % loop through each value of 'n'
    G= expm(-1i*H*n(i));        % reference the i-th value of 'n'
    psi= G*psi0;
    I1(i)= (abs(psi(1,1))).^2;  %store values from each iteration 
    I2(i)= (abs(psi(2,1))).^2;  %store values from each iteration
end
plot(n,I1)    %now you have 2 vectors to plot
hold on       %don't repace the line you just plot; add to it instead
plot(n,I2)