Problem in legend plot in case of empty variable [ ]

Hello everyone, I have a problem in a legend plot. In particular, the code is:

plot(x1,y1,'b')
plot(x2,y2,'r')
plot(x3,y3,'k')
plot(x4,y4,'m')

legend ('Plot 1', 'Plot 2', 'Plot 3', 'Plot 4')

For example, if y3 = [ ], the plot of y4 will be associated to 'Plot 3'. I would like that in case of y3 = [ ] the legend skips the corresponding 'Plot 3' and associate y4 to 'Plot 4'.

Any ideas?

Thank you all

Answer 1

[Rik]

I am going to assume your numbered variables are just to make this example easy to understand. If not: you should consider indexing a cell array instead.

As for you question: you can set the DisplayName property.

x1=rand(10,1);y1=rand(size(x1));
x2=rand(10,1);y2=rand(size(x1));
x4=rand(10,1);y4=rand(size(x1));
x3=[];y3=[];
h{1}=plot(x1,y1,'b','DisplayName','Plot 1');
hold on
h{2}=plot(x2,y2,'r','DisplayName','Plot 2');
h{3}=plot(x3,y3,'k','DisplayName','Plot 3');
h{4}=plot(x4,y4,'m','DisplayName','Plot 4');

legend([h{:}])

[Federico Giannetti]

Perfect.

Thank you! It's working.

[Rik]

You're welcome. If this solved your issue, please consider marking it as accepted answer. If not, feel free to comment with remaining issues.