indexing question
have a look at ?"[.data.frame"; what you need is the following: dat <- data.frame(a = rbinom(20, 1, 0.5), x = rnorm(20), y = rnorm(20)) dat dat[dat$a == 1, ] I hope it helps. Best, Dimitris
Bunny, lautloscrew.com wrote:
Hi all, i have a pretty easy indexing question, at least i believe so. The main reason i post it here, is that brackets and $ are hard to google. How do I index correctly, if i just want to display the whole dataset conditioned on the fact that some particular column equals one. I know i can do something like: data$somecolumn[data$particularcol ==1] . That will show all "some column" values where the particular column is 1. Unfortunately something like : data[data$particularcol ==1] does not work to get the whole matrix. is there some easy way except the % in % stuff ? Thx in advance
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Dimitris Rizopoulos Assistant Professor Department of Biostatistics Erasmus Medical Center Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands Tel: +31/(0)10/7043478 Fax: +31/(0)10/7043014