Is this what you were looking for: > x <- scan(textConnection(" 1372.23718 2.277450e+04 + 74.48333 5.494448e+01 + 226.63590 6.023199e+02 + 1947.17564 4.044391e+04 + 178.79615 3.970006e+02 + 657.56857 3.396852e+04 + 251.60519 1.239538e+03 + 78.53846 7.473607e+01 + 140.37564 2.395830e+02 + 358.13718 1.508718e+03"), what=0) Read 20 items > closeAllConnections() > mydata <- matrix(x, ncol=2, byrow=TRUE) > mydata [,1] [,2] [1,] 1372.23718 22774.50000 [2,] 74.48333 54.94448 [3,] 226.63590 602.31990 [4,] 1947.17564 40443.91000 [5,] 178.79615 397.00060 [6,] 657.56857 33968.52000 [7,] 251.60519 1239.53800 [8,] 78.53846 74.73607 [9,] 140.37564 239.58300 [10,] 358.13718 1508.71800 > # top 3 indices > order(mydata[,2], decreasing=TRUE)[1:3] [1] 4 6 1 > # print out the ordered data > mydata[order(mydata[,2], decreasing=TRUE),] [,1] [,2] [1,] 1947.17564 40443.91000 [2,] 657.56857 33968.52000 [3,] 1372.23718 22774.50000 [4,] 358.13718 1508.71800 [5,] 251.60519 1239.53800 [6,] 226.63590 602.31990 [7,] 178.79615 397.00060 [8,] 140.37564 239.58300 [9,] 78.53846 74.73607 [10,] 74.48333 54.94448 >
On Mon, Jun 23, 2008 at 9:35 PM, Gundala Viswanath <[EMAIL PROTECTED]> wrote: > Hi, > > How can I get the top-3 index (sorted by "var") of the following > matrix? > >> print(mydata) > var > [1,] 1372.23718 2.277450e+04 > [2,] 74.48333 5.494448e+01 > [3,] 226.63590 6.023199e+02 > [4,] 1947.17564 4.044391e+04 > [5,] 178.79615 3.970006e+02 > [6,] 657.56857 3.396852e+04 > [7,] 251.60519 1.239538e+03 > [8,] 78.53846 7.473607e+01 > [9,] 140.37564 2.395830e+02 > [10,] 358.13718 1.508718e+03 > > > - Gundala Viswanath > Jakarta - Indonesia > > ______________________________________________ > 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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? ______________________________________________ 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.