[R] Help with "apply"

[Dennis Murphy]

Hi:

Are you *sure* that's what you want to do?

> y - x[,5] * gtemp[5]
 [1]  0.10116205  2.46220119  3.04966544  0.56074569 -1.14872521 -0.89275228
 [7]  3.52161381  0.64880894  0.70167063 -0.06120996
> identical(as.vector(ycorr), y - x[,5] * gtemp[5])
[1] TRUE

Perhaps you ought to explain what you are trying to compute, because
your inner loop is returning y[i] - x[, 5] * gtemp[5] for each i,
where 5 = ncol(x).

Dennis

On Thu, May 12, 2011 at 2:23 PM, M.Ribeiro <mresendeufv at yahoo.com.br> wrote:
> Hello R gurus,
>
> I have a simple routine using for loops that i was just trying to make it
> faster
>
> y <- rnorm(10)
> Nindiv <- 10
> x <-matrix(sample(c(0:2),50,re = T),10)
> gtemp <- rnorm(10)
> ycorr <- array(0,c(Nindiv,1))
> for (i in 1:Nindiv) {
>        for (k in 1:ncol(x)) {
>                ycorr[i] <- y[i] - x[i,k]*gtemp[k]
>        }
> }
>
> It works fine but I wanted to make it faster and I think an apply function
> could probably solve this problem.
> Any suggestions? Thanks
>
> --
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