Boxplot with double y-axis

Hello All, I want to plot a boxplot with a double y-axis (reference figure is attached). Actually, I have two sets of variables. One variable value will display on the left side and another variable value will display on the right of the y-axis.

Answer 1

[Aditya]

MATLAB doesn't support drawing two boxplots as you are suggesting. But, you can use a work around.

The idea is to create empty box plots.

load carsmall
yyaxis left 
boxplot([Acceleration nan(100,1)])
yyaxis right
boxplot([nan(100,1) Horsepower])

You can see that [Acceleration nan(100,1)] creates a 100x2 matrix with second column as nan.

• When I use boxplot for left axis, it plots two curves at x-location 1 and 2 for each column. As the second column is nans, second boxplot is empty.
• Now, for second plot, I want location-1 to be empty (as I already have plotted acceleration on that), so I use [nan(100,1) Horsepower], which will draw Horsepower at x-location 2.

For your refereimage, you will need to do something like this

yyaxis left 
boxplot([l1 nan(100,1) l2 nan(100,1) l3 nan(100,1)])
yyaxis right
boxplot([nan(100,1) r1 nan(100,1) r2 nan(100,1) r3])

This is not what you are looking for but I think closest:

• The colors need to be tackled. You can change individual colors as shown here
• Labels need to be tackled

Answer 2

[Aditya]

Hi,

You can use the yyaxis command.

The key idea is to activate the axis that you want to plot. Suppose I have two ys : y1 and y2, I want to plot y1 on the left side and y2 on the right side, I can do as shown here:

yyaxis left
plot(x,y1);
yyaxis right
plot(x,y2);

You can read more about it at the example shown here.

Answer 3

[sunny kant]

Thank you Aditya for your reply. This will work for the plot command. I am applying for the boxplot, it is not working.

[Aditya]

I think it is working as intended, as there are two boxplots at the same 'x'.

A simple example is here

load carsmall
yyaxis left 
boxplot(Acceleration)
yyaxis right
boxplot(Horsepower)

What you are looking for is a no superposition.

Answer 4

[sunny kant]

Aditya, I have also tried this, but two variables (means two box) go inside each other. I want to separate it (image attached for your reference) because it can be two separate boxes for two variables.

Answer 5

[sunny kant]

Thank you Aditya, it worked for me.