firsthalf <- myframe[v1,] or firsthalf <- subset(myframe, number %in% v1) ----- A R learner. -- View this message in context: http://r.789695.n4.nabble.com/Randomly-split-a-sample-in-two-equal-subsamples-tp3021140p3021353.html Sent from the R help mailing list archive at Nabble.com.