CODEWITHSUNDEEP
matlabplot
Rohit Pandey
Rohit Pandey

Reputation: 2681

Plotting multiple series in matlab

The following commands produce some very strange results - 

 plotyy(1:3,2:4,3:5,4:6)
hold on
plotyy(1:3,2.1:4.1,3:5,4.1:6.1)

I basically want to plot two different series on the left y axes and two more series on the right y axes. The above commands work fine for the left series, but produce weird results for the right one. The second green line doesn't look like it should.

Upvotes: 4

Views: 2482

Answers (2)

Bas Swinckels
Bas Swinckels

Reputation: 18488

Indeed pretty weird behavior. For fun, select the 'hand' tool in the plot window and then drag the graph around, you see that only one of the two green curves moves and that on the right side there are two sets of labels drawn on top of each other. I would qualify this as a bug in matlab (far from the only ugly behavior in Matlab's plots). This seems to be a workaround for what you want to achieve:

[AX, H1, H2] =  plotyy(1:3, [2:4;2.1:4.1], 3:5,[4:6;4.1:6.1]);
>> set(H1, 'color','b')
>> set(H2, 'color','g')

Note that this only works if the two left plots have the same set of x-values, and similar for the right plots, like in your case. A=[4000;0;1]. But this is a workaround, the real solution is given by slbass.

Upvotes: 4

slbass
slbass

Reputation: 526

The problem that you are having is related to the way that the plotyy creates they plot. plotyy creates two different axes that it plots on, and then mounts them into a single figure. When you issue the hold on command, you are only freezing one of the axes. To fix this, you need to hold each one individually, and then plot back onto them using the plot command.

[ax,hl,hr] = plotyy(1:3,2:4,3:5,4:6);
hold(ax(1), 'on')  
hold(ax(2), 'on')
plot(ax(1), 1:3,2.1:4.1) 
plot(ax(2), 3:5,4.1:6.1)

Upvotes: 7

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