Suppose I have a large matrix:
M <- matrix(rnorm(1e7),nrow=20)
Further suppose that each column represents a sample. Say I would like to apply t.test() to each column, is there a way to do this that is much faster than using apply()?
apply(M, 2, t.test)
It took slightly less than 2 minutes to run the analysis on my computer:
> system.time(invisible( apply(M, 2, t.test)))
user system elapsed
113.513 0.663 113.519