Message-ID: <0AF8C77E-FD6B-4CFA-BA18-2430F16F56E9@gmail.com>
Date: 2011-01-05T19:16:47Z
From: Kevin Ummel
Subject: Match numeric vector against rows in a matrix?
Two posts in one day is not a good day...and this question seems like it should have an obvious answer:
I have a matrix where rows are unique combinations of 1's and 0's:
> combs=as.matrix(expand.grid(c(0,1),c(0,1)))
> combs
Var1 Var2
[1,] 0 0
[2,] 1 0
[3,] 0 1
[4,] 1 1
I want a single function that will give the row index containing an exact match with vector x:
> x=c(0,1)
The solution needs to be applied many times, so I need something quick -- I was hoping a base function would do it, but I'm drawing a blank.
Thanks!
Kevin