Yao He wrote > Dear All: > > I want to calculate the mean and sd for each column in a data.frame. > > Taking data(iris) for example: > I tried sapply(iris[,-5],mean,na.rm=T) or sapply(iris[,-5],sd,na.rm=T) > to calculate the mean and sd .But sapply() transfer a function per > time. How to transfer two functions in a time to generate a data.frame > like this: > > Sepal.Length Sepal.Width Petal.Length Petal.Width > mean 5.84333 3.05733 3.758000 1.199333 > SD 0.82806 0.43586 1.765298 0.762237 > > > Thanks a lot > > Yao He > > -- > ————————————————————————— > Master candidate in 2rd year > Department of Animal genetics & breeding > Room 436,College of Animial Science&Technology, > China Agriculture University,Beijing,100193 > E-mail:
> yao.h.1988@ > —————————————————————————— > > ______________________________________________ > R-help@ > 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. Or maybe using apply .... # data d <- iris[,-5] # apply function a <-data.frame(apply(d, 2, function(x) c(mean=mean(x), sd=sd(x)))) # print(a) output Sepal.Length Sepal.Width Petal.Length Petal.Width mean 5.8433333 3.0573333 3.758000 1.1993333 sd 0.8280661 0.4358663 1.765298 0.7622377 HTH Pete -- View this message in context: http://r.789695.n4.nabble.com/how-to-apply-two-or-more-functions-to-each-columns-in-a-time-tp4654001p4654004.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.
