Dear All: I was trying to get the lengths of vectors using "length" in tapply as follows:
ni<-tapply(data[,2], data[,2], length, na.rm=TRUE) but it did not work for me. I am not sure what I am doing wrong. I am not sure if I should use different function. Here is the data: ============ data<-matrix(c(8,24,0,0,16,32,6,0,16,7,4,4,9,5,8,18,2,0,4,0,8,3,1,5,24,12,2,8,1,8, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,3,3),30,2) The answer should be: ni: 18 , 10 , 2 thank you very much Steven -- Steven M. Stoline 1123 Forest Avenue Portland, ME 04112 [email protected] [[alternative HTML version deleted]] _______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-sig-teaching
