[R] R annoyances
Uwe Ligges
ligges at statistik.uni-dortmund.de
Thu May 19 16:49:16 CEST 2005
Chalasani, Prasad wrote:
> Dear R Folks,
> I'm a big fan of R, but there are a couple of things
> that repeatedly annoy me, and I wondered if anyone
> has neat ways to deal with them.
>
> (a) When using "apply" row-wise to a matrix, it returns
> the results column-wise, and to preserve the original
> orientation, I've to do a transpose. E.g. I've to keep
> doing a transpose, which I consider to be quite annoying.
>
> transformed.mtx <- t(apply( mtx, 1, exp))
I'd rather type
exp(mtx)
> (b) When extracting 2 or more columns of a matrix,
> R returns the result as a matrix, BUT when extracting
> just one column, it returns a vector/array, rather than
> a matrix, so I've to keep doing as.matrix, which is annoying.
>
> sub.mtx <- as.matrix(mtx[,1])
>
> Of course I could write a suitable function
> cols <- function(mtx,range) as.matrix(mtx[, range])
> but then I lose the syntactic sugar of being able to say "[,1]".
The docs suggest:
mtx[ , 1, drop = FALSE]
Uwe Ligges
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