How to display sample size on each box of a boxplot? Many boxes have different sample sizes.

Say I graph a boxplot figure with 4 boxes. I would like to display the sample size, n, for each of the individual boxes on the figure. How do I do this?

Thanks!

Answer 1

[Star Strider]

I suggest text. You'll likely have to experiment with it a bit to get the effect you want.

An example:

D = normrnd(0, 1, 10, 4) + repmat([0 1 2 3]*0.5,10,1);
M = mean(D);
G = {'A' 'B' 'C' 'D'};
N = [12  5  8  10];

figure(1)
boxplot(D,G)
for k1 = 1:size(D,2)
    text(k1-0.15,M(k1)*1.2, sprintf('N = %d', N(k1)), 'FontSize',8);
end

[George McFadden]

Thanks Star Strider. Text solves many questions like this one. I am surprised that boxplot does not have a built-in option for this. Its a common feature of boxplots in publications.

[Star Strider]

It's always my pleasure to help — especially a fellow 'Hoo!