R help - Apr 2015 - your suggestions in MRMs

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



 		 	   		  
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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

Hi Sarah,

Thanks for the reply. I again looked at the example, but I did not find the way
to
calculate the location variable. All example in the document
("ecodist") has the Euclidean distance. did not find the example to
conceal the absolute location. There are some example:

page 21 and 22 : iris.md <- distance(iris[,1:4], "mahal"): it is
calculated distance matrix using four variables (I understood this one)

page 26: space.d <- distance(space, "eucl"), here space is XY
coordinate,
so on



I am just wondering how I can conceal my absolute location (XY) and make my
data compatible to your data set so that I can use your functions. I am sorry
for bothering you, Sarah.

example of my data set: column names (site,
XY coordinates, temp, years)

site1, 25.01;34.78 (XY cordicnate),
35degree celcius; year2001

site1, 25.01;34.78 (XY cordicnate), 33degree celcius;
year2002

site2, 25.05; 35.56 (XY coordinate); 37degree
celcius; year2001

site2, 25.05; 35.56 (XY coordinate);
32degree celcius; year2002





Thanks

 

======
> Date: Wed, 8 Apr 2015 14:23:27 -0400
> Subject: Re: [R] your suggestions in MRMs
> From: sarah.goslee at gmail.com
> To: kristi.glover at hotmail.com
> CC: r-help at r-project.org
> 
> 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
 		 	   		  
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