###--- >>> `which' <<<----- Which indices are TRUE ?

	## alias	 help(which)

##___ Examples ___:

which(LETTERS == "R")
which(ll <- c(T,F,T,NA,F,F,T))#> 1 3 7
names(ll) <- letters[seq(ll)]
which(ll)
which((1:12)%%2 == 0) # which are even?
str(which(1:10 > 3, arr.ind=TRUE))

( m <- matrix(1:12,3,4) )
which(m %% 3 == 0)
which(m %% 3 == 0, arr.ind=TRUE)
rownames(m) <- paste("Case",1:3, sep="_")
which(m %% 5 == 0, arr.ind=TRUE)

dim(m) <- c(2,2,3); m
which(m %% 3 == 0, arr.ind=FALSE)
which(m %% 3 == 0, arr.ind=TRUE)

vm <- c(m);  dim(vm) <- length(vm) #-- funny thing with  length(dim(..)) == 1
which(vm %% 3 == 0, arr.ind=TRUE)

## Keywords: 'logic', 'attribute'.


