Hi Hamada, Could the following be helpful?
"dtf" is your data.frame nr <- nrow(dtf) new.dtf <- data.frame(Site.No=seq(1,nr/2)) new.dtf$XXX <- dtf[seq(1,nr,2),3] new.dtf$YYY <- dtf[seq(2,nr,2),3] or new.mat <- numeric() new.mat <- cbind(new.mat,dtf[seq(1,nr,2),3]) new.mat <- cbind(new.mat,dtf[seq(2,nr,2),3]) Regards, Pascal ----- Mail original ----- De : Hamada Elsayed Ali <medo_bot...@hotmail.com> À : r-help@r-project.org Cc : Envoyé le : Jeudi 8 mars 2012 18h20 Objet : [R] Problem with a Matrix Dear All, I have a problem in making a matrix from a data. I did a summary data from a big data frame using (ddply), the resulting table is like that: Site.No Plant.Name Cover.Percentage 1 XXX 15 1 YYY 20 2 XXX 18 2 YYY 21 3 XXX 14 3 YYY 26 I need to convert it to the following: XXX YYY 1 15 20 2 18 21 3 14 26 I tried for the whole day yesterday but I can't solve it. Could you please help me. Thanks in advance for all of you, Hamada -- View this message in context: http://r.789695.n4.nabble.com/Problem-with-a-Matrix-tp4455954p4455954.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
