Try the following:
y1 = [85 83 82 87; 81 79 84 86; 82 81 89 87; 89 85 87 80; 90 91 85 87];
figure(1),
b = bar(y1,'stacked');
labels = arrayfun(@(value) [num2str(value,'%2.2f'),'%'],y1,'UniformOutput',false);
xticklabels({'NB','BLR','MLP','J48','CART'});
ylabel('\bfAccuracy in %','color','b');
%
for k = 1:4
xtips1 = b(k).XEndPoints;
ytips1 = b(k).YEndPoints;
labels1 = string(b(k).YData);
text(xtips1,ytips1,labels1,'HorizontalAlignment','center',...
'VerticalAlignment','cap')
end
ax = gca;
darkGreen = [1,0,1];
ax.XColor = darkGreen;
ax.XAxis.FontSize = 10;
ax.YAxis.FontSize = 10;
ax.FontWeight = 'bold';
hold off
legend({'2500 Dataset','5000 Dataset','7500 Dataset','10000 Da,taset'},'NumColumns',2),legend boxoff
