got it many thanks
Steven On Tue, Sep 9, 2014 at 11:16 PM, Mark Daniel Ward <[email protected]> wrote: > Dear Steven, > > If you remove the parameter: > na.rm=TRUE > then your example seems to work fine for me. Good luck! > > Best wishes, > Mark > > Mark Daniel Ward, Ph.D. > Associate Professor and Undergraduate Chair > Department of Statistics > Purdue University > 150 North University Street > West Lafayette, IN 47907-2067 > [email protected] > phone: (765) 496-9563 > > > > > On 9/9/14, 11:12 PM, Steven Stoline wrote: > >> 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
