MATLAB: How to label the secondary axis of a graph

plotyysecondary axisylabel

Hi,

This is a simple question, but I can't seem to find the answer to it anywhere… how do I add a label to the secondary (RHS) axis of a graph made using plotyy? I am curretly using ylabel but of course only one axis can be labelled that way.

Thanks

Best Answer

The 4th syntax of ylabel shows explixitly than you can 'refer' to a specific axis.

Which means that you have to use the last syntax of plotyy to retrieve the handles to both axes and then feed it to ylabel. You can also set the labels as shown in the example (of the documentation).

An example with ylabel

figure
x = 0:0.01:20;
y1 = 200*exp(-0.05*x).*sin(x);
y2 = 0.8*exp(-0.5*x).*sin(10*x);
[AX,H1,H2] = plotyy(x,y1,x,y2,'plot');
ylabel(AX(1),'Something')
ylabel(AX(2),'Else')

Related Solutions

MATLAB: Do the x-tick labels overlap when I update them in a plot created using PLOTYY

Using PLOTYY creates two overlapping X-Axes along with the desired set of Y-Axes.

Subsequently changing the x-tick labels using DATETICK or set(gca, ‘XTickLabel’, …) only changes the x-tick labels of one of these two x-axes resulting in the overlap.

In order to work around this issue, you can delete the tick labels from both sets of x-axes and then assign new x-tick labels. The following code illustrates this workaround:

x=[1:10]
y1=2*x;
y2=3*x;
plotyy(x, y1, x, y2)
[AX,H1,H2] = plotyy(x, y1, x, y2)  
set(AX, 'xTickLabel','') % delete the x-tick labels
datetick('x',2) % update the x-tick labels

In the above code, [AX,H1,H2] = plotyy(...) returns the handles of the two axes created in AX and the handles of the graphics objects from each plot in H1 and H2. AX(1) is the left axes and AX(2) is the right axes.

Alternatively, you can set the dateticks on both axes, as in the example below:

x = datenum(0:0.01:20); 
y1 = 200*exp(-0.05*x).*sin(x); 
y2 = 0.8*exp(-0.5*x).*sin(10*x); 
AX = plotyy(x,y1,x,y2,'plot'); 
datetick(AX(1),'x',20) 
datetick(AX(2),'x',20)

Another option is to link the properties of both axes as shown in the example below:

x=[1:10];
y1=2*x;
y2=3*x;
[AX,H1,H2] = plotyy(x,y1,x,y2,'plot');
linkprop(AX,{'Xlim','XTickLabel','Xtick'});           % Link the limits of both axes, and the labels
axes(AX(2));datetick('x',20)                            % Now use DATETICK
axis tight

MATLAB: Datetick with plotyy

datetick(AX(1),'x','yyyy')

If that still doesn't do what you want you can clear other axis Ticks

set(AX(2),'XTick',[])

Best Answer

Related Solutions

MATLAB: Do the x-tick labels overlap when I update them in a plot created using PLOTYY

MATLAB: Datetick with plotyy

Related Question