Re: [Rd] x[1,], x[1,,], x[1,,,], ...

From: Robin Hankin <r.hankin_at_noc.soton.ac.uk>
Date: Tue 29 Nov 2005 - 10:41:33 GMT

Hi everyone

apltake(x,1)

[where apltake() is part of library(magic)]

does this.

best wishes

Robin

On 23 Nov 2005, at 10:50, Henrik Bengtsson wrote:

> Hi,
>
> is there a function in R already doing what I try to do below:
>
> # Let 'x' be an array with *any* number of dimensions (>=1).
> x <- array(1:24, dim=c(2,2,3,2))
> ...
> x <- array(1:24, dim=c(4,3,2))
>
> i <- 2:3
>
> ndim <- length(dim(x))
> if (ndim == 1)
> y <- x[i]
> else if (ndim == 2)
> y <- x[i,]
> else if (ndim == 3)
> y <- x[i,,]
> else ...
>
> and so on. My current solution is
>
> ndim <- length(dim(x))
> args <- rep(",", ndim)
> args[1] <- "i"
> args <- paste(args, collapse="")
> code <- paste("x[", args, "]", sep="")
> expr <- parse(text=code)
> y <- eval(expr)
>
> ndim <- length(dim(x))
> args <- rep(",", ndim)
> args[1] <- "i"
> args <- paste(args, collapse="")
> code <- paste("x[", args, "]", sep="")
> expr <- parse(text=code)
> y <- eval(expr)
>
> Is there another way I can do this in R that I have overlooked?
>
> /Henrik
>
> ______________________________________________
> R-devel@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel

--
Robin Hankin
Uncertainty Analyst
National Oceanography Centre, Southampton
European Way, Southampton SO14 3ZH, UK
  tel  023-8059-7743

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Received on Tue Nov 29 21:44:56 2005

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