Dear all,
I'm new to matrix operations in R. I couln't find a solution to the
following problem among earlier help mails or in An introd to R, I guess
because the question is really basic.
I want to extract all above the diagonal, i.e. from
1 2 3 4
1 0 26 49 49
2 26 0 44 40
3 49 44 0 21
4 49 40 21 0
I want
26
49
44
49
40
21
Thanks in advance!
Sincerely,
Tord
-----------------------------------------------------------------------
Tord Sn?ll
Avd. f v?xtekologi, Evolutionsbiologiskt centrum, Uppsala universitet
Dept. of Plant Ecology, Evolutionary Biology Centre, Uppsala University
Villav?gen 14
SE-752 36 Uppsala, Sweden
Tel: 018-471 28 82 (int +46 18 471 28 82) (work)
Tel: 018-25 71 33 (int +46 18 25 71 33) (home)
Fax: 018-55 34 19 (int +46 18 55 34 19) (work)
E-mail: Tord.Snall at ebc.uu.se
Check this: http://www.vaxtbio.uu.se/resfold/snall.htm!
At 16:55 22/05/2003 +0200, vous avez ?crit:>Dear all, > >I'm new to matrix operations in R. I couln't find a solution to the >following problem among earlier help mails or in An introd to R, I guess >because the question is really basic. > >I want to extract all above the diagonal, i.e. from > > 1 2 3 4 >1 0 26 49 49 >2 26 0 44 40 >3 49 44 0 21 >4 49 40 21 0 > >I want > >26 >49 >44 >49 >40 >21If your matrix is named M, this should do it: M[row(M) < col(M)] EP>Thanks in advance! > > >Sincerely, >Tord
Tord Snall wrote:> Dear all, > > I'm new to matrix operations in R. I couln't find a solution to the > following problem among earlier help mails or in An introd to R, I guess > because the question is really basic. > > I want to extract all above the diagonal, i.e. from > > 1 2 3 4 > 1 0 26 49 49 > 2 26 0 44 40 > 3 49 44 0 21 > 4 49 40 21 0 > > I want > > 26 > 49 > 44 > 49 > 40 > 21 >X[row(X) < col(X)] Uwe Ligges> Thanks in advance! > > > Sincerely, > Tord > > ----------------------------------------------------------------------- > Tord Sn?ll > Avd. f v?xtekologi, Evolutionsbiologiskt centrum, Uppsala universitet > Dept. of Plant Ecology, Evolutionary Biology Centre, Uppsala University > Villav?gen 14 > SE-752 36 Uppsala, Sweden > Tel: 018-471 28 82 (int +46 18 471 28 82) (work) > Tel: 018-25 71 33 (int +46 18 25 71 33) (home) > Fax: 018-55 34 19 (int +46 18 55 34 19) (work) > E-mail: Tord.Snall at ebc.uu.se > Check this: http://www.vaxtbio.uu.se/resfold/snall.htm! > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help
A[row(A)<col(A)] url: www.econ.uiuc.edu Roger Koenker Dept. of Economics UCL, email rkoenker at uiuc.edu Department of Economics Drayton House, vox: 217-333-4558 University of Illinois 30 Gordon St, fax: 217-244-6678 Champaign, IL 61820 London,WC1H 0AX, UK vox: 020-7679-5838 On Thu, 22 May 2003, Tord Snall wrote:> Dear all, > > I'm new to matrix operations in R. I couln't find a solution to the > following problem among earlier help mails or in An introd to R, I guess > because the question is really basic. > > I want to extract all above the diagonal, i.e. from > > 1 2 3 4 > 1 0 26 49 49 > 2 26 0 44 40 > 3 49 44 0 21 > 4 49 40 21 0 > > I want > > 26 > 49 > 44 > 49 > 40 > 21 > > > Thanks in advance! > > > Sincerely, > Tord > > ----------------------------------------------------------------------- > Tord Snäll > Avd. f växtekologi, Evolutionsbiologiskt centrum, Uppsala universitet > Dept. of Plant Ecology, Evolutionary Biology Centre, Uppsala University > Villavägen 14 > SE-752 36 Uppsala, Sweden > Tel: 018-471 28 82 (int +46 18 471 28 82) (work) > Tel: 018-25 71 33 (int +46 18 25 71 33) (home) > Fax: 018-55 34 19 (int +46 18 55 34 19) (work) > E-mail: Tord.Snall at ebc.uu.se > Check this: http://www.vaxtbio.uu.se/resfold/snall.htm! > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help >
> A <- array(1:12, dim=c(3,4))> A[col(A)>row(A)] [1] 4 7 8 10 11 12 This is described in Modern Applied Statistics with S (p. 43 of the 3rd edition; I'm pretty sure I've seen it in the 4th edition, but I don't have that handy just now.) hth. spencer graves Tord Snall wrote:> Dear all, > > I'm new to matrix operations in R. I couln't find a solution to the > following problem among earlier help mails or in An introd to R, I guess > because the question is really basic. > > I want to extract all above the diagonal, i.e. from > > 1 2 3 4 > 1 0 26 49 49 > 2 26 0 44 40 > 3 49 44 0 21 > 4 49 40 21 0 > > I want > > 26 > 49 > 44 > 49 > 40 > 21 > > > Thanks in advance! > > > Sincerely, > Tord > > ----------------------------------------------------------------------- > Tord Sn?ll > Avd. f v?xtekologi, Evolutionsbiologiskt centrum, Uppsala universitet > Dept. of Plant Ecology, Evolutionary Biology Centre, Uppsala University > Villav?gen 14 > SE-752 36 Uppsala, Sweden > Tel: 018-471 28 82 (int +46 18 471 28 82) (work) > Tel: 018-25 71 33 (int +46 18 25 71 33) (home) > Fax: 018-55 34 19 (int +46 18 55 34 19) (work) > E-mail: Tord.Snall at ebc.uu.se > Check this: http://www.vaxtbio.uu.se/resfold/snall.htm! > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help
Dear Tord, At 04:55 PM 5/22/2003 +0200, Tord Snall wrote:>I'm new to matrix operations in R. I couln't find a solution to the >following problem among earlier help mails or in An introd to R, I guess >because the question is really basic. > >I want to extract all above the diagonal, i.e. from > > 1 2 3 4 >1 0 26 49 49 >2 26 0 44 40 >3 49 44 0 21 >4 49 40 21 0 > >I want > >26 >49 >44 >49 >40 >21 >If you want the result as a one-column matrix, as.matrix(mat[upper.tri(mat)]) will do the trick. John ----------------------------------------------------- John Fox Department of Sociology McMaster University Hamilton, Ontario, Canada L8S 4M4 email: jfox at mcmaster.ca phone: 905-525-9140x23604 web: www.socsci.mcmaster.ca/jfox
On Thu, 22 May 2003, Tord Snall wrote:> Dear all, > > I'm new to matrix operations in R. I couln't find a solution to the > following problem among earlier help mails or in An introd to R, I guess > because the question is really basic. > > I want to extract all above the diagonal, i.e. from > > 1 2 3 4 > 1 0 26 49 49 > 2 26 0 44 40 > 3 49 44 0 21 > 4 49 40 21 0 >In addition to the solution suggested by other people there are built-in functions upper.tri and lower.tri for doing this sort of thing, so x[upper.tri(x)] -thomas
Dear all, Thanks for, as always the quick replies! I have a suggestion: add the upper.tri() and lower.tri() under "See Also" in the diag() help page. I searched for a such function there, and I can see that diag() can be found unde "See also" for upper.tri(). Sincerely, Tord At 08:45 2003-05-22 -0700, Thomas Lumley wrote:>On Thu, 22 May 2003, Tord Snall wrote: > >> Dear all, >> >> I'm new to matrix operations in R. I couln't find a solution to the >> following problem among earlier help mails or in An introd to R, I guess >> because the question is really basic. >> >> I want to extract all above the diagonal, i.e. from >> >> 1 2 3 4 >> 1 0 26 49 49 >> 2 26 0 44 40 >> 3 49 44 0 21 >> 4 49 40 21 0 >> > >In addition to the solution suggested by other people there are built-in >functions upper.tri and lower.tri for doing this sort of thing, so > > x[upper.tri(x)] > > > -thomas > >----------------------------------------------------------------------- Tord Sn?ll Avd. f v?xtekologi, Evolutionsbiologiskt centrum, Uppsala universitet Dept. of Plant Ecology, Evolutionary Biology Centre, Uppsala University Villav?gen 14 SE-752 36 Uppsala, Sweden Tel: 018-471 28 82 (int +46 18 471 28 82) (work) Tel: 018-25 71 33 (int +46 18 25 71 33) (home) Fax: 018-55 34 19 (int +46 18 55 34 19) (work) E-mail: Tord.Snall at ebc.uu.se Check this: http://www.vaxtbio.uu.se/resfold/snall.htm!