function start_pool(poolsize_set)

% poolsize_set = 2;

%If no pool, do not create new one

poolobj = gcp('nocreate'); 

if isempty(poolobj)

    parpool(poolsize_set);

else %if isempty(poolobj)

    %current poolsize

    poolsize = poolobj.NumWorkers;

    if poolsize ~= poolsize_set

        delete(gcp('nocreate'));

        parpool(poolsize_set);

    end %if poolsize ~= 2

end %if isempty(poolobj)