Nested for loop not iterating

I have a nested for loop needed to do a gridsearch to do a linear fit of a model with two unknown constants. As far as I can tell, these for loops are not iterating because i and j both show a value of 1 in the workspace. What am I doing wrong?

Thanks for any help.

agrid=[1:0.1:100];
bgrid=[.5:.0001:1.5];

lenagrid=length(agrid);
lenbgrid=length(bgrid);

for i = 1:lenagrid
    for j = 1:lenbgrid
        a_p = agrid(i)
        b_p=bgrid(j);
        fhat(i,j)=(a_p(i))-(b_p(j)).*magrange;
        TSE(i,j)=sum((fhat-magrange).^2);
    end
end

[Daniel M]

You're trying to access the jth element of b_p, but it is only length 1.

[per isakson]

Was there an error message? What did it say?

Answer 1

[per isakson]

I'm just guessing. Replace

a_p = agrid(i)
b_p=bgrid(j);
fhat(i,j)=(a_p(i))-(b_p(j)).*magrange;

by

fhat(i,j) = ( agrid(i) - bgrid(i) ).*magrange;