Error using - Matrix dimensions must agree. HELP

addpath('C:\Program Files\MATLAB\R2012a\Matlab\q1')

load x.dat

load y.dat

x=(X-mean(X))./std(X);

y=(Y-mean(Y))./std(Y);

m=length(x);

x=[ones(m,1),x];

alpha=0.07;

theta=[0;0];

MAX_ITR=100;

J=zeros(MAX_ITR,1);

for num_iteration=1:MAX_ITR

J(num_iteration)=(0.5/m).*((x*theta)-y)'*((x*theta)-y);

grad=(1/m).*x'*((x*theta)-y);

theta=theta-alpha.*grad;

end

fprintf('Theta values are ...\n')

theta

R=(y-x*theta).^2;

fprintf('RMS values is ....\n')

sqrt(sum®./m)

plot(J)

Error using - Matrix dimensions must agree.

Can anyone help me how to get rid of this error?

Answer 1

[James Tursa]

The best course of action usually is to get into the debugger and stop your code at the line that is generating the error, and then examine the variable sizes. Once you figure out which variables are the wrong (or unexpected) size, you can work back in the code to figure out why and work toward a solution.