R-helpers, Below is a simple example of some output that I am getting while trying to work with a data frame in R 2.12.1 for Mac. -----
testdat <- data.frame(matrix(ncol=10, nrow=10))
colnames(testdat) <- c('a','b','c','d','e','f','g','h','i','j')
testdat[seq(1,10,3),] <- c(1,0,0,0,0,0,0,0,0,0)
testdat
a b c d e f g h i j 1 1 0 0 0 0 1 0 0 0 0 2 NA NA NA NA NA NA NA NA NA NA 3 NA NA NA NA NA NA NA NA NA NA 4 0 0 0 0 0 0 0 0 0 0 5 NA NA NA NA NA NA NA NA NA NA 6 NA NA NA NA NA NA NA NA NA NA 7 0 0 1 0 0 0 0 1 0 0 8 NA NA NA NA NA NA NA NA NA NA 9 NA NA NA NA NA NA NA NA NA NA 10 0 0 0 0 0 0 0 0 0 0 ----- The output is not what I would have anticipated. Since seq(1,10,3) gives the vector [1 4 7 10], I expected rows 1, 4, 7 and 10 of the data.frame "testdat" to contain the same data, a 1 for variable 'a' and zeros for all other variables. I guess I assumed the assigment would proceed by rows, but it appears from the resulting output to be proceeding by columns. Can someone point out how I can modify this simple code so that the assignments proceed by rows? Thank you. Brant