> a <- 1:24
> dim(a) <- c(2,3,2,2)
> permutation <- c(1,2,4,3)
> b <- aperm(a,permutation)
> a[1,3,2,1]
[1] 11
>
> Expr <- paste("b[", paste(c(1,3,2,1)[permutation], collapse=","), "]")
> eval(parse(text=Expr))
[1] 11Ugly, I think, but effective. hope this helps. spencer graves
Robin Hankin wrote:
Hi everyone.
I'm playing with aperm():
a <- 1:24 dim(a) <- c(2,3,2,2) permutation <- c(1,2,4,3) b <- aperm(a,permutation)
So if my understanding is right,
a[1,3,2,1] == b[c(1,3,2,1)[permutation] ]
but this isn't what I want because the RHS evaluates to a vector, and I am trying to identify a single element of b.
How do I modify the RHS to give what I want?
Following aren't right either: b[as.vector(c(1,3,2,1)[permutation]) ] b[as.list(c(1,3,2,1)[permutation]) ]
OBattempt:
eval(parse(text=paste("b[",paste(c(1,3,2,1)[permutation],collapse=","),"]")))
which DOES work, but is ghastly!
______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
