[R] vectorial search for elements with certain attributes

infochat at gmx.net infochat at gmx.net
Thu May 19 11:58:17 CEST 2011


I have 2 vectors A and B. For each element of B I'd like to find the index of the next higher or equal element in A. And I'd like to store it effectiv. E.g.:
A <- c(1,3,7,8,10)
B <- c(5,8)

result: 3, 4

I have a possibility but for long vectors it works not very effectiv:

ans <- sapply(B, function(x) which.max(A[A < x]) )
as.integer(ans + 1)

Is there anyone how has a better idea?
Thank you for your help,
Thomas.
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