I am starting with a matrix in which rows are vegetation plots and columns are various characteristics including ID# and elevation. I removed elevation and ID columns to avoid having those characteristics influence the distances between points which I calculated using the "dist" command. The resulting distance file was then used in isoMDS. What I want to know is whether I can reattach the ID and elevation onto the point location information given from isoMDS? or is it possible that the order given in the isoMDS output is not the same as the order of the original data used to calculate distances? Thanks, Carrie Pucko University of Vermont
I don't know for sure about isoMDS, but package vegan is a good place to start with a very good viginette. Stephen On Thu, Sep 4, 2008 at 5:02 PM, Carolyn A. Pucko <cpucko at uvm.edu> wrote:> > I am starting with a matrix in which rows are vegetation plots and columns > are various characteristics including ID# and elevation. I removed elevation > and ID columns to avoid having those characteristics influence the distances > between points which I calculated using the "dist" command. The resulting > distance file was then used in isoMDS. > > What I want to know is whether I can reattach the ID and elevation onto the > point location information given from isoMDS? or is it possible that the > order given in the isoMDS output is not the same as the order of the > original data used to calculate distances? > > Thanks, > Carrie Pucko > University of Vermont > > ______________________________________________ > R-help at 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. >-- Stephen Sefick Research Scientist Southeastern Natural Sciences Academy Let's not spend our time and resources thinking about things that are so little or so large that all they really do for us is puff us up and make us feel like gods. We are mammals, and have not exhausted the annoying little problems of being mammals. -K. Mullis
On Thu, 4 Sep 2008, Carolyn A. Pucko wrote:> > I am starting with a matrix in which rows are vegetation plots and columns > are various characteristics including ID# and elevation. I removed elevation > and ID columns to avoid having those characteristics influence the distances > between points which I calculated using the "dist" command. The resulting > distance file was then used in isoMDS. > > What I want to know is whether I can reattach the ID and elevation onto the > point location information given from isoMDS? or is it possible that the > order given in the isoMDS output is not the same as the order of the original > data used to calculate distances?The order is the same. From the help page Value: Two components: points: A k-column vector of the fitted configuration. ... and see how it describes 'the fitted configuration'. BTW, it is regarded as basic courtesy to credit the work of others: isoMDS is from package MASS.> > Thanks, > Carrie Pucko > University of Vermont > > ______________________________________________ > R-help at 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.-- Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595