Vertical boxplot?

Hi,

I have a data matrix A(15,1000) for which I would like to plot the statistics of the date contained in each of the 15 rows in a Box-Whisker style plot. That is easily accomplished with boxplot. However, I was unable to make the boxes line up in the direction of the y-axis instead of the x-axis. Basically, I would like to have a vertical box plot, where the y-axis would go from y(1) to y(15).

How can I do this?

Answer 1

[Walter Roberson]

"boxplot(X) produces a box plot of the data in X. If X is a matrix, there is one box per column; "

Since you want one box per row instead of per column, you need to transpose the data you sent to boxplot

boxplot(A.', 'orientation', 'horizontal');

[Andreas]

Thanks, Walter. That at least plots the boxes vertically as I want it. However, the positions at which the boxes are drawn still go from 1 to 15 and not y(1) to y(15). I basically want to create the boxes first and then add another line plot that shows some other data and how it compares to the boxes. So, what I want is the following:

x = 1:1:15; y = f(x);

figure; boxplot(X','orientation','horizontal'); hold on; plot(x,y);

[Walter Roberson]

It is better to get in the habit of using .' instead of ' as otherwise you are going to have a hard time figuring out why you are having problems working with complex values.

Anyhow, like this:

figure;

h = boxplot(A.', 'orientation', 'horizontal');

for K = 1 : length(h)

set(h(K), 'YData', f(get(h(K),'YData')));

end

hold on

plot(f(1:size(A,1)));

Note that A must not be a vector: vectors always produce a single box, no matter what the orientation of the vector.

Answer 2

[Tom Lane]

Could it be that you want to use the 'positions' argument?

rowvals = [1 2 4 8]';
x = bsxfun(@plus,rowvals,randn(4,20));
boxplot(x','ori','horizontal','positions',rowvals)

Then maybe get rid of the group numbers:

set(gca,'ytickmode','auto')
set(gca,'yticklabelmode','auto')