Re: [R] Array arithmetic

From: Henrique Dallazuanna <wwwhsd_at_gmail.com>
Date: Thu, 06 Mar 2008 16:12:49 -0300

Hum you are rigth, I forgot of 'else'.

On 06/03/2008, Benilton Carvalho <bcarvalh_at_jhsph.edu> wrote:
> no, it won't.
>
> you're doing the right math on the "valid" subset... but you're not
> returning the zeros where needed.... therefore, the whole thing will
> get recycled to match the dimensions.
>
>
> b
>
>
> On Mar 6, 2008, at 2:03 PM, Henrique Dallazuanna wrote:
>
> > I think this should work:
> >
> > array(A[abs(B) > 10e-5]/B[abs(B) > 10e-5], dim=c(L, M, N, P))
> >
> > On 06/03/2008, Gang Chen <gangchen6_at_gmail.com> wrote:
> >> I have two arrays A and B with dimensions of (L, M, N, P) and (L, M,
> >> N), and I want to do
> >>
> >> for (i in 1:L) {
> >> for (j in 1:M) {
> >> for (k in 1:N) {
> >> if (abs(B[i, j, k]) > 10e-5) C[i, j, k,] <- A[i, j, k,]/B[i, j, k]
> >> else C[i, j, k,] <- 0
> >> }
> >> }
> >> }
> >>
> >> How can I get C more efficiently than looping?
> >>
> >> Thanks,
> >> Gang
> >>
> >> ______________________________________________
> >> R-help_at_r-project.org mailing list
> >> https://stat.ethz.ch/mailman/listinfo/r-help
> >> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> >> and provide commented, minimal, self-contained, reproducible code.
> >>
> >
> >
> > --
> > Henrique Dallazuanna
> > Curitiba-Paraná-Brasil
> > 25° 25' 40" S 49° 16' 22" O
> >
> > ______________________________________________
> > R-help_at_r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
>
>
>

-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

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Received on Thu 06 Mar 2008 - 19:16:30 GMT

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