Hi, THANK YOU ALL for the prompt reply. cheers.
----- Original Message ----- From: Robin Hankin <[EMAIL PROTECTED]> Date: Wednesday, September 6, 2006 1:42 am Subject: Re: [R] What is the matrix version of min() To: Tong Wang <[EMAIL PROTECTED]> Cc: R help <r-help@stat.math.ethz.ch> > Tong > > you need to use apply(). The second argument specifies whether > you want to work with rows or columns. The point of this is that > min() and max() operate on vectors and give a single value, > and you want to "apply" this function to all rows or all columns: > > > a <- matrix(rnorm(30),5,6) > > apply(a,2,max) > [1] 2.6413241 0.9842076 1.7989560 0.6999855 2.0542201 0.1162821 > > apply(a,1,max) > [1] 1.1771370 0.9811693 2.6413241 0.9842076 2.0542201 > > > > HTH > > rksh > > > On 6 Sep 2006, at 09:37, Tong Wang wrote: > > > Hi, > > Is there a function which operates on a matrix and return a > > vector of min/max of each rol/col ? > > say, X= 2, 1 > > 3, 4 > > min.col(X)=c(2,1) > > > > thanks a lot. > > > > tong > > > > ______________________________________________ > > R-help@stat.math.ethz.ch 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. > > -- > Robin Hankin > Uncertainty Analyst > National Oceanography Centre, Southampton > European Way, Southampton SO14 3ZH, UK > tel 023-8059-7743 > > > > > ______________________________________________ R-help@stat.math.ethz.ch 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.
