Is this what you want: > x <- matrix(1:16,4) > rownames(x) <- colnames(x) <- LETTERS[1:4] > x A B C D A 1 5 9 13 B 2 6 10 14 C 3 7 11 15 D 4 8 12 16 > require(reshape) > # create single list > z <- melt(x) > z X1 X2 value 1 A A 1 2 B A 2 3 C A 3 4 D A 4 5 A B 5 6 B B 6 7 C B 7 8 D B 8 9 A C 9 10 B C 10 11 C C 11 12 D C 12 13 A D 13 14 B D 14 15 C D 15 16 D D 16 > # now extract just the lower matrix > z[as.vector(lower.tri(x)),] X1 X2 value 2 B A 2 3 C A 3 4 D A 4 7 C B 7 8 D B 8 12 D C 12
On Thu, Oct 9, 2008 at 11:31 AM, Marten Winter <[EMAIL PROTECTED]> wrote: > Heja, > > I've some bigger distance-matrices like this: > > num [1:3231, 1:3231] 0.000 0.176 0.176 0.176 0.176 ... > - attr(*, "dimnames")=List of 2 > ..$ : chr [1:3231] "A" "B" "C" "D" ... > ..$ : chr [1:3231] A" "B" "C" "D" . > > I actually want to convert them into a 2 column dataframe like this: > > > data.frame': 10439361 obs. of 2 variables: > $ dist: num 0.000 0.176 0.176 0.176 0.176 ... > $ spec: Factor w/ 219680 levels "A B",..: 1508 26 27 60 61 62 63 340 > 413 414 ... > > preferred appearance: > > values species > 1 0.0000000 A A > 2 0.1761717 A B > 3 0.1761717 A C > 4 0.1761717 A D > 5 0.1761717 A E > > > BUT, I don't need the entries where I have the same distance: "A B" vs. > "B A", cause the inflate heavily my workspace. > I know "stack", but I don't know, why but it seems that stack has > limitations in size (?), it doesn't work. > I never really understood "reshape". > > May someone has a nice way to reshape ;O) a matrix. > > THANKS, > cheers from autumnlike Halle, > Marten > > -- > > *Marten Winter* > > Helmholtz Centre for Environmental Research -- UFZ > Department of Community Ecology > Helmholtz-Zentrum für Umweltforschung GmbH - UFZ > Sektion Biozoenoseforschung > Theodor-Lieser-Str. 4 > D-06120 Halle (Saale) > Germany > > > phone: ++49 (0) 345 558-5316 / fax:++49 (0) 345 558-5329 > E-mail: [EMAIL PROTECTED] > http://www.ufz.de/index.php?en=7081 > DAISIE - Delivering Alien Invasive Species Inventories for Europe > http://www.europe-aliens.org > > > > [[alternative HTML version deleted]] > > > ______________________________________________ > 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 that 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.
