[R] threshold matrix
rolf.turner at xtra.co.nz
Sat Apr 30 03:07:54 CEST 2011
On 30/04/11 02:44, Alaios wrote:
> Thanks a lot.
> I finally used
> M2<- M
> M2[M< thresh]<- 0
> M2[M>= thresh]<- 1
> as I noticed that this one line
> M2<- as.numeric( M< thresh )
> vectorizes my matrix.
> One more question I have two matrices that only differ slightly. What will be the easiest way to compare and find the cells that are not the same?
(1) M2 <- 0 +(M >= thresh)
is one line (and is sexier! :-) ).
(2) which(A !=B, arr.ind = TRUE)
or (possibly more sensibly)
which (abs(A-B) > sqrt(.Machine$double.eps), arr.ind = TRUE)
should solve your ``One more question''.
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