ncores = 12;
matlabpool('open', 'local', ncores); % another form of matlabpool

wi = zeros(1,1000);
parfor k=1:1000
    w = getCurrentWorker;
    
    wi(k) = get(w, 'ProcessId')
end

matlabpool('close');

pid = unique(wi);
core = zeros(1, 1000);
for k=1:ncores
    core(wi == pid(k)) = k;
end

plot(core, 'o')
title('Allocation of CPUs')
xlabel('Index')
ylabel('CPU ID/core')