Good point. Following Andy's comment sd(matrix(sort(x), nc=12)) could also be used if you want them broken up by 6 smallest, next 6 smallest, etc. although there might be differences in the case of ties.
Using tapply here are a number of ways of breaking it up (the first three give the same answer as sd(matrix(x,nc=12))) while the others form the groups in different ways: tapply(x, gl(12, 6), sd) tapply(x, rep(1:12, each = 6), sd) tapply(sort(x), gl(12, 6), sd) tapply(x, rep(1:12, 6), sd) tapply(sort(x), rep(1:6, 12), sd) tapply(sort(x), rep(1:6, each = 12), sd) On 4/28/06, Liaw, Andy <[EMAIL PROTECTED]> wrote: > You didn't say _how_ you want the vector to be broken up, > so you get two different answers from Uwe and Gabor. Uwe's > answer group every six elements into one group, in the order > they appear in the vector (which, BTW, can be simplified to > just sd(matrix(x, ncol=12)). Gabor's answer put the smallest > six into one group, the next smallest six into the second > group and so on. You'll have to decide which is the one > you want. > > Andy > > From: sumanta basak > > > > Hi R-Experts, > > > > I have a vector of length 72. I want to break it into 12 > > parts and want to take standerd deviation of each group. > > Please help me in this regard. > > > > Thanks, > > Sumanta. > > > > > > --------------------------------- > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > [email protected] mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide! > > http://www.R-project.org/posting-guide.html > > > > > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
