You have two matrix multiplications in the offending line H+l1*eye(nh,nh))\(H'*Data.y);
So, the problem is one of the following:
- Variable i1 is a not square(*), or
- size(H',2) ~= size(Data.y,1)(*), or
- didn't intend to use matrix multiplication but element-wise which is the "dot" operator ".*"
Don't know which of the above is the actual case nor necessarily the answer you need as didn't try to read the code but looking through your algorithm for the intended result ensuring that you can actually perform a legal matrix multiplication if that's what is wanted or if it is computation in the numerator/denominator of the expression that is supposed to be element-by-element, then fix the operator to do that instead.
() Matrix multiplication requires A*B have dimensions such that are [m x n][n x q] with result of [m x q].
