(This article was first published on Stats raving mad » R, and kindly contributed to R-bloggers)
Instead of the factor() function which usually applies after defining a vector there’s the gl() base function to do this in one step, eg
freq <- c(204,6,1,211,13,5,357,44,38,92,34,49) row <- gl(4,3,length=12) col <- gl(3,1,length=12) > col [1] 1 2 3 1 2 3 1 2 3 1 2 3 Levels: 1 2 3 tt <- data.frame(freq,row,col) > xtabs(tt) col row 1 2 3 1 204 6 1 2 211 13 5 3 357 44 38 4 92 34 49
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