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)