[R-sig-eco] Stepwise multiple linear regression analysis??

[Yong Zhang]

Hi all,

Appologize for any inconvience that I brought to you in advance.

Now, I have 15 samples with species and environment data, the number of the environmental variable is 21. When I try to conduct the CCA in PC-ORD, the program stoped immediately, and I was notified that " the number of environmental factors should be less than the samples.What I would like to do is exclude some of the environmental variables. 

Could anyone tell me is the stepwise multiple linear regression analysis is proper for my objective?? any hint or suggestion will be greatly appreciated. 

All the best

 

2010-12-28 



  
Yong Zhang, Ph.D.
Lab of aquatic insects & stream ecology
Dept.of Entonology, Nanjing Agricultural University
Nanjing, 210095,China 
Phone number:  (+86) -25-84395241
E-mail:2010202035 at njau.edu.cn



发件人： r-sig-ecology-request 
发送时间： 2010-12-28  18:58:05 
收件人： r-sig-ecology 
抄送： 
主题： R-sig-ecology Digest, Vol 33, Issue 20 
 
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Today's Topics:
   1. Which analysis should I take? (Yong Zhang)
   2. Re: Which analysis should I take? (Eduard Sz?cs)
----------------------------------------------------------------------
Message: 1
Date: Tue, 28 Dec 2010 13:53:15 +0800
From: "Yong Zhang" <2010202035 at njau.edu.cn>
To: "r-sig-ecology" <r-sig-ecology at r-project.org>
Subject: [R-sig-eco] Which analysis should I take?
Message-ID: <201012281353150154522 at njau.edu.cn>
Content-Type: text/plain; charset="gb2312"
Hello all, 
Thing is like that now I have 14 sampling sites with the species and environment data. Which analysis is the best choice for determining the difference/dissimilarity among those sites. I have installed the R (2.12.2 version), which soft package or function should I take to achieve my objective.
Thanks very much for your time and suggestion.
Best Regards
Yong
2010-12-28 
  
Yong Zhang, Ph.D.
Lab of aquatic insects & stream ecology
Dept.of Entonology, Nanjing Agricultural University
Nanjing, 210095,China 
Phone number:  (+86) -25-84395241
E-mail:2010202035 at njau.edu.cn
------------------------------
Message: 2
Date: Tue, 28 Dec 2010 10:16:36 +0100
From: Eduard Sz?cs <szoe8822 at uni-landau.de>
To: r-sig-ecology at r-project.org
Subject: Re: [R-sig-eco] Which analysis should I take?
Message-ID: <4D19AAF4.2050900 at uni-landau.de>
Content-Type: text/plain
Hai Yong,
have a look at the vegan package: with the function vegdist() you can 
calculate dissimilarity indices.
There are also some good tutorials on vegan available on the net.
HTH,
Eduard
Am 28.12.2010 06:53, schrieb Yong Zhang:
> Hello all,
>
> Thing is like that now I have 14 sampling sites with the species and environment data. Which analysis is the best choice for determining the difference/dissimilarity among those sites. I have installed the R (2.12.2 version), which soft package or function should I take to achieve my objective.
>
> Thanks very much for your time and suggestion.
>
> Best Regards
>
> Yong
> 2010-12-28
>
>
>
>
> Yong Zhang, Ph.D.
> Lab of aquatic insects&  stream ecology
> Dept.of Entonology, Nanjing Agricultural University
> Nanjing, 210095,China
> Phone number:  (+86) -25-84395241
> E-mail:2010202035 at njau.edu.cn
>
>
> _______________________________________________
> R-sig-ecology mailing list
> R-sig-ecology at r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-ecology
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