[R] compute variance of every column in a matrix without a loop
tlumley at u.washington.edu
Sun Mar 17 23:50:00 CET 2002
On Sat, 16 Mar 2002, Francisco J Molina wrote:
> Is it possible to compute the variance of every column in a matrix
> without a loop?
No, but you can make it look as if there's no loop.
You can hide the for() loop inside a function with
apply(m, 2, var)
if the reason you want to avoid a loop is to make your code look simpler.
In 1.5.0 you will be able to do
if the reason is to have the loop take place in compiled code and be
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