plotyy

(Not recommended) Create graph with two y-axes

plotyy is not recommended. Use yyaxis instead. For more information, see Compatibility Considerations.

Syntax

plotyy(X1,Y1,X2,Y2)
plotyy(X1,Y1,X2,Y2,function)
plotyy(X1,Y1,X2,Y2,'function1','function2')
plotyy(AX1,___)
[AX,H1,H2] = plotyy(___)


Description

plotyy(X1,Y1,X2,Y2) plots Y1 versus X1 with y-axis labeling on the left and plots Y2 versus X2 with y-axis labeling on the right.

plotyy(X1,Y1,X2,Y2,function) uses the specified plotting function to produce the graph.

function can be either a function handle or a character vector specifying plot, semilogx, semilogy, loglog, stem, or any MATLAB^® function that accepts the syntax

h = function(x,y)

For example,

plotyy(x1,y1,x2,y2,@loglog) % function handle
plotyy(x1,y1,x2,y2,'loglog') % character vector

Function handles enable you to access user-defined local functions and can provide other advantages. For more information on using function handles, see Create Function Handle.

plotyy(X1,Y1,X2,Y2,'function1','function2') uses function1(X1,Y1) to plot the data for the left axis and function2(X2,Y2) to plot the data for the right axis.

plotyy(AX1,___) plots the data using the axes specified by AX1 for the first set of data, instead of using the current axes. Specify AX1 as a single axes object or a vector of the two axes objects returned by a previous call to plotyy. If you specify a vector, then plotyy uses the first axes object in the vector. Use this option with any of the input argument combinations in the previous syntaxes.

[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.

Examples

Plot Two Data Sets with Different y-Axes

Plot two data sets on one graph using two y-axes.

x = 0:0.01:20;
y1 = 200*exp(-0.05*x).*sin(x);
y2 = 0.8*exp(-0.5*x).*sin(10*x);

figure % new figure
plotyy(x,y1,x,y2)

Add Title and Axis Labels

Plot two data sets using a graph with two y-axes. Add a title and axis labels.

x = 0:0.01:20;
y1 = 200*exp(-0.05*x).*sin(x);
y2 = 0.8*exp(-0.5*x).*sin(10*x);

figure % new figure
[hAx,hLine1,hLine2] = plotyy(x,y1,x,y2);

title('Multiple Decay Rates')
xlabel('Time (\musec)')

ylabel(hAx(1),'Slow Decay') % left y-axis 
ylabel(hAx(2),'Fast Decay') % right y-axis

Change Line Styles

Plot two data sets using a graph with two y-axes. Change the line styles. Starting in R2014b, you can use dot notation to set properties. If you are using an earlier release, use the set function instead.

x = 0:0.01:20;
y1 = 200*exp(-0.05*x).*sin(x);
y2 = 0.8*exp(-0.5*x).*sin(10*x);

[hAx,hLine1,hLine2] = plotyy(x,y1,x,y2);
hLine1.LineStyle = '--';
hLine2.LineStyle = ':';

Combine Different Types of Plots

Plot two data sets using a graph with two y-axes. Use a line plot for the data associated with the left y-axes. Use a stem plot for the data associated with the right y-axes.

x = 0:0.1:10;
y1 = 200*exp(-0.05*x).*sin(x);
y2 = 0.8*exp(-0.5*x).*sin(10*x);

figure 
plotyy(x,y1,x,y2,'plot','stem')

Use Right y-Axis for Two Data Sets

Plot three data sets using a graph with two y-axes. Plot one set of data associated with the left y-axis. Plot two sets of data associated with the right y-axis by using two-column matrices.

x = linspace(0,10);
y1 = 200*exp(-0.05*x).*sin(x);
y2 = 0.8*exp(-0.5*x).*sin(10*x);
y3 = 0.2*exp(-0.5*x).*sin(10*x);

figure
[hAx,hLine1,hLine2] = plotyy(x,y1,[x',x'],[y2',y3']);

Extended Capabilities

GPU Arrays

Accelerate code by running on a graphics processing unit (GPU) using Parallel Computing Toolbox™.

Usage notes and limitations:

• This function accepts GPU arrays, but does not run on a GPU.

For more information, see Run MATLAB Functions on a GPU (Parallel Computing Toolbox).

Distributed Arrays

Partition large arrays across the combined memory of your cluster using Parallel Computing Toolbox™.

Usage notes and limitations:

• This function operates on distributed arrays, but executes in the client MATLAB.

For more information, see Run MATLAB Functions with Distributed Arrays (Parallel Computing Toolbox).

Version History

Introduced before R2006a

R2016a: plotyy is not recommended

plotyy is not recommended. Use yyaxis instead. There are no plans to remove plotyy.

Starting in R2016a, use the yyaxis function to create charts with two y-axes. The yyaxis function has several advantages over the plotyy function.

• Unlike plotyy, the yyaxis function creates one Axes object with two y-axes. plotyy creates two overlaid Axes objects that can get out of sync.

• You can use yyaxis with any 2-D plotting function. plotyy is limited to working with plotting functions of the form function(x,y). It does not work with other plotting functions, such as errorbar.

This table shows some typical usages of plotyy and how to update your code to use yyaxis instead.

Not Recommended	Recommended
plotyy(x1,y1,x2,y2)	yyaxis left plot(x1,y1) yyaxis right plot(x2,y2)
plotyy(x1,y1,x2,y2,... 'function1','function2')	yyaxis left function1(x1,y1) yyaxis right function2(x2,y2)