MATLAB: How to add additional plots to either of the two y-axes when using the PLOTYY function

MATLABmultipleplotyy

I am using the PLOTYY function to create a single plot with one x-axis and two y-axes. I am plotting a time-series vector on each of these y-axes using the following statement:

plotyy(x, y1, x, y2, 'plot');

I would like to know how to add additional plots to either of these two y-axes. For example, I may want 3 time-series plots for the first y-axis and 2 time-series plots for the second y-axis.

Best Answer

You may plot multiple lines on both axes by either concatenating the data or using the HOLD function. For example:

% define the data
figure
x = 0:0.01:20;
y1 = 200*exp(-0.05*x).*sin(x);
y2 = 1./exp(-0.05*x).*cos(x);
y3 = 200*cos(x);
y4 = 0.8*exp(-0.5*x).*sin(10*x);
y5 = 0.8*exp(-0.5*x).*cos(x);
% plotting the data on the two axes 
[AX H1 H2] = plotyy(x, [y1; y2; y3], x, [y4; y5], 'plot');

Note that each of the time-series vectors y1 through y5 are row vectors. Their vertical concatenation allows us to plot all of them simultaneously.

Using the HOLD function:

figure
%plot data on both axes
[AX H1 H2] = plotyy(x, y1, x, y4, 'plot');
%hold both axes
hold(AX(1));
hold(AX(2));
%plot additional data to the axes
plot(AX(1),x,y2,'c');
plot(AX(1),x,y3,'r');
plot(AX(2),x,y5,'m');

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: How to add the third time series to the chart which is to be read on the right hand axis with the first two time series plotted on the same chart on the left hand axis in MATLAB 7.6 (R2008a)

You may plot multiple lines on both axes by either concatenating the data or using the HOLD function. For example, let’s say that you want to plot 2 time-series plots for the first y-axis and 1 time-series plot for the second y-axis.

% define the data
figure;
x = 0:0.01:20;
y1 = 200*exp(-0.05*x).*sin(x);
y2 = 1./exp(-0.05*x).*cos(x);
y3 = 200*cos(x);
% plotting the data on the two axes 
[AX H1 H2] = plotyy(x, [y1; y2], x, [y3]);

Note that each of the time-series vectors y1 through y3 are row vectors. Their vertical concatenation allows us to plot all of them simultaneously.

Alternatively, you can do this using the HOLD function:

[AX H1 H2] = plotyy(x, y1, x, y3);
hold(AX(1), 'on')
plot(AX(1),x,y2,'c');

If your time series are stored in a “timeseries” object, you will need to extract the data from them to plot. For example,

t1 = timeseries(rand(1, 10), 1:10);
x = t1.Time
y = squeeze(t1.Data)

Best Answer

Related Solutions

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

MATLAB: How to add the third time series to the chart which is to be read on the right hand axis with the first two time series plotted on the same chart on the left hand axis in MATLAB 7.6 (R2008a)

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