plot function legend is wrong.

Hi All,

Can anybody give me some pointers on why the legend in the following plot is wrong. I use a loop to plot two variables, one is an array.

figure (55)

for i = 1:152

plot(t3,PowerAuts(:,:,i)); hold on;

end

hold on

plot(t3, MeanDailyPwr1,'color','k','LineWidth',4);

legend('MeanDailyPwr1','Orientation','horizontal')

grid on

ylim([0 40]);

yticks([0:5:40]);

xlim([t3(1) t3(end)])

ax.FontSize = 22;

xlabel('Time (hh:mm)','FontSize',24)

ylabel('Load Demand (kW)','FontSize',24)

title('Daily Load Demand','FontSize',28)

I want to display the variable MeanDailyPower1 in the legend but it is the wrong color at the moment.

[Antoni Garcia-Herreros]

You may want to check here or here

You should reference your plot:

   pMean=plot(t3, MeanDailyPwr1,'color','k','LineWidth',4);
   l=legend(pMean,'MeanDailyPwr1','Orientation','horizontal');
  

[Ben Whitby]

I got it. Thank you.

Answer 1

[Star Strider]

The legend is probably picking up the first line plotted, that by default is blue.

Perhaps this —

figure (55)

for i = 1:152

plot(t3,PowerAuts(:,:,i)); hold on;

end

hold on

hpMDP = plot(t3, MeanDailyPwr1,'color','k','LineWidth',4);

legend(hpMDP, 'MeanDailyPwr1','Orientation','horizontal')

grid on

ylim([0 40]);

yticks([0:5:40]);

xlim([t3(1) t3(end)])

ax.FontSize = 22;

xlabel('Time (hh:mm)','FontSize',24)

ylabel('Load Demand (kW)','FontSize',24)

title('Daily Load Demand','FontSize',28)

Including the handle to the 'MeanDailyPower' plot specifies what the legend is to refer to.

.

Answer 2

[Dave B]

The legend is labeling the first line in the chart rather than the last one. An easy way to specify which line should be labeled in the legend is to grab the output from plot and pass that into the legend function

a = rand(10);
hold on
for i = 1:size(a,1)
    plot(a(i,:))
end
aveline=plot(mean(a),'k','LineWidth',2);
legend(aveline,'The Average')