[R] your suggestions in MRMs

[Sarah Goslee]

Kristi,

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.

Sarah

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
http://www.functionaldiversity.org