Index of item in matrix
Or more simply:
> set.seed(1)
> A <- array(rnorm(12), dim=c(3,4))
> which(round(A) == 1, arr.ind = TRUE)
row col
[1,] 2 2
[2,] 1 4
Though, the original post may need more clarification.
Sundar
Spencer Graves wrote:
Satisfying what conditions? Does the following example help you get what you want?
> set.seed(1) > A <- array(rnorm(12), dim=c(3,4)) > > sel <- (round(A)==1) > sel
[,1] [,2] [,3] [,4] [1,] FALSE FALSE FALSE TRUE [2,] FALSE TRUE FALSE FALSE [3,] FALSE FALSE FALSE FALSE
> cbind(row(A)[sel],col(A)[sel])
[,1] [,2] [1,] 2 2 [2,] 1 4 Spencer Graves John Janmaat wrote:
Hello All, Is there a fast way to find the index(row and column) of a point in a matrix? Thanks, John.
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