Hamid, your 'solveq' function is clearly intended only for an 'f' input argument consisting of a column vector, not the 3-by-n size you mentioned. The function would have to be modified to handle other than a column vector for 'f'.
It looks as if the requirements for the input arguments of 'solveq' are:
1) K should be some n-by-n square matrix
2) f should be an n-by-1 vector
3) bc should have two columns and the first column should consist of some subset of the integers from 1 to n. Consequently there should be fewer than n rows in bc.
Note that if 3) is violated, you will get an error message at the line
fdof(pdof)=[];
If K has fewer columns than rows, you will get an error message at
s=K(fdof,fdof)\(f(fdof)-K(fdof,pdof)*dp);
If f has more than one column, its columns other than the first will be ignored.
By the way, your 'end' in 'solveq' is placed one line too early and would cause 'Q' to be output as all zeros.
