Try ?r2dtable
On 4/27/07, Nick Cutler <[EMAIL PROTECTED]> wrote: > I would like to be able to randomise presence-absence (i.e. binary) > matrices whilst keeping both the row and column totals constant. Is > there a function in R that would allow me to do this? > > I'm working with vegetation presence-absence matrices based on field > observations. The matrices are formatted to have sites as rows and > species as columns. The presence of a species on a site is indicated > with a 1 (absence is obviously indicated with a 0). > > I would like to randomise the matrices many times in order to construct > null models. However, I cannot identify a function in R to do this, and > the programming looks tricky for someone of my limited skills. > > Can anybody help me out? > > Many thanks, > > Nick Cutler > > Institute of Geography > School of Geosciences > University of Edinburgh > Drummond Street > Edinburgh EH8 9XP > United Kingdom > > Tel: 0131 650 2532 > Web: http://www.geos.ed.ac.uk/homes/s0455078 > > ______________________________________________ > [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 > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ [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 and provide commented, minimal, self-contained, reproducible code.
