[R] Problem: using cor.test with by( )

[Liviu Andronic]

On Sun, Mar 30, 2008 at 7:11 PM, Che-hsu (Joe) Chang <chjchang at gmail.com> wrote:
>  Basically, I want to calculate the correlation between variable A and B for
>  every subject in my study. (yep, that simple)
>
>  What I did is this:
>  by(data, id, function (x) cor.test(A,B, data=x))

This recent thread [1] might prove of interest.
Liviu

[1] http://www.nabble.com/p-value-in-Spearman-rank-order-tt15738907.html