matlabpool doesn't exist in Matlab 2015 and above

[patricksnape]

Therefore, all the lines where you check (matlabpool('size')==0) throw an exception. This can be fixed by replacing them with isempty(gcp('nocreate')).

However, I'm not sure if that call works on older versions of Matlab. If someone confirms this still works then I can make a PR to fix this.

[zhusz]

Yes, thanks! And actually we can let the 'if' statement always go to the parfor branch.