Create Chart with Two y-Axes
This example shows how to create a chart with y-axes on the left and right sides using the
yyaxis function. It also shows how to label each axis, combine multiple plots, and clear the plots associated with one or both of the sides.
Plot Data Against Left y-Axis
Create axes with a y-axis on the left and right sides. The
yyaxis left command creates the axes and activates the left side. Subsequent graphics functions, such as
plot, target the active side. Plot data against the left y-axis.
x = linspace(0,25); y = sin(x/2); yyaxis left plot(x,y);
Plot Data Against Right y-Axis
Activate the right side using
yyaxis right. Then plot a set of data against the right y-axis.
r = x.^2/2; yyaxis right plot(x,r);
Add Title and Axis Labels
Control which side of the axes is active using the
yyaxis left and
yyaxis right commands. Then, add a title and axis labels.
yyaxis left title('Plots with Different y-Scales') xlabel('Values from 0 to 25') ylabel('Left Side') yyaxis right ylabel('Right Side')
Plot Additional Data Against Each Side
Add two more lines to the left side using the
hold on command. Add an errorbar to the right side. The new plots use the same color as the corresponding y-axis and cycle through the line style order. The
hold on command affects both the left and right sides.
hold on yyaxis left y2 = sin(x/3); plot(x,y2); y3 = sin(x/4); plot(x,y3); yyaxis right load count.dat; m = mean(count,2); e = std(count,1,2); errorbar(m,e) hold off
Clear One Side of Axes
Clear the data from the right side of the axes by first making it active, and then using the
yyaxis right cla
Clear Axes and Remove Right y-Axis
Clear the entire axes and remove the right y-axis using
Now when you create a plot, it only has one y-axis. For example, plot three lines against the single y-axis.
xx = linspace(0,25); yy1 = sin(xx/4); yy2 = sin(xx/5); yy3 = sin(xx/6); plot(xx,yy1,xx,yy2,xx,yy3)
Add Second y-Axis to Existing Chart
Add a second y-axis to an existing chart using
yyaxis. The existing plots and the left y-axis do not change colors. The right y-axis uses the next color in the axes color order. New plots added to the axes use the same color as the corresponding y-axis.
yyaxis right rr1 = exp(xx/6); rr2 = exp(xx/8); plot(xx,rr1,xx,rr2)