[R] your suggestions in MRMs

Sarah Goslee sarah.goslee at gmail.com
Wed Apr 8 20:23:27 CEST 2015


The row names are utterly arbitrary. Each row is a separate site, and
sitelocation is a location variable (both intended to conceal the
absolute location, which is confidential since it's on private
property). It is NOT the Euclidean distance, nor is a row representing
a pair of sites.

If you look at the full example, dist() is used to calculate the
Euclidean distance as part of the MRM code.


On Wed, Apr 8, 2015 at 1:49 PM, Kristi Glover <kristi.glover at hotmail.com> wrote:
> Hi R Users,
> I was trying to  perfom multiple regression on resemblance matrices (MRMs). This technique in avaiable  in "ecodist" package  and looked at the example data to know how I need to organize my data set. I think the data is distance matrix but I was wondering the rows name. For example, there are (these are the subset of the data of "graze")
>          sitelocation forestpct
> 1.1.2001    12.187743     63.88
> 1.2.2001    12.186077     71.33
> 2.1.2001    12.406362     72.45
> 2.2.2001    12.416265     77.13
> 3.1.1998     8.409213     18.35
> if we look at the first row, 1.1.2001: sitelocation (column) is 12.187.. which is the euclidean distance between two points (XY cordinates). But I was confused at the row name where 1.1.2001 which is to me is site1 and site1 of 2001. Isn't it supposed to be "0" if both are the same site.  I think I misunderstood it. Any one can help me about what it is?
> I put the example for your reference
> install.packages("ecodist")
> library(ecodist)
> data(graze)
> graze[1:5,1:2]
> Thanks for your help
> KG

Sarah Goslee

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