# MATLAB: Cannot give the value to part of the matrix in parallel computing

MATLABparallel computing

As I'm trying to wrtie a code for matrix multiplying with the 'parfor', I've got an error that 'cannot verify the type of variable C'. Could anyone tell me how to manipulate part of C'value ?
``parfor r = 1:d        i = mod(r-1,b)+1;        j = floor(r-1/a)+1;        s = min(i*subsize,m);   t = min(j*subsize,n);        tmp = zeros(s-(i-1)*subsize,t-(j-1)*subsize);        for k = 1:c           q = min(k*subsize,l);           tmp = tmp+A((i-1)*subsize+1:s,(k-1)*subsize+1:q)*B((k-1)*subsize+1:q,(j-1)*subsize+1:t);        end        C((i-1)*subsize+1:s,(j-1)*subsize+1:t) = tmp;    end``

``% Assumed a, b, c, d, l, m, n, subsize, A, B are all define above% Using a nested function so that input arguements don't need to be passed to unitOfWorkp = gcp;for r = 1:d    f(r) = p.parfeval(@unitOfWork,5);endfor r = 1:d    [~,i,j,s,t,tmp] = f.fetchNext();    C((i-1)*subsize+1:s,(j-1)*subsize+1:t) = tmp;end    function [i,j,s,t,tmp] = unitOfWork()        i = mod(r-1,b)+1;        j = floor(r-1/a)+1;        s = min(i*subsize,m);   t = min(j*subsize,n);        tmp = zeros(s-(i-1)*subsize,t-(j-1)*subsize);        for k = 1:c            q = min(k*subsize,l);            tmp = tmp+A((i-1)*subsize+1:s,(k-1)*subsize+1:q)*B((k-1)*subsize+1:q,(j-1)*subsize+1:t);        end    endend``