How to change x-axis with boxplot

I have boxplot like this

X = randn(100,82);
boxplot(X)

How to change the x-axis to only show the indices 20,40,60, and 80.

This code is not working

set(gca,'XTick',(20:20:80));

Answer 1

[Voss]

Like this?

X = randn(100,82);
boxplot(X)
xt = 20:20:80;
set(gca,'XTick',xt,'XTickLabel',xt);

Or like this?

xt = 20:20:80;
boxplot(X(:,xt))
set(gca,'XTickLabel',xt);