try this
data = [1 2 1 3 2;
2 3 1 2 3;
3 2 1 2 1];
figure();
ax = axes();
bar(data', 'stacked')
xlabel('Users');
ylabel('Capacity(kW)/Cost(PKR)');
ax.XTickLabel = {'user1', 'user2', 'user3', 'user4', 'user5'};
legend({'class1', 'class2', 'class3'});
