[R-sig-eco] Fwd: help

[Mahnaz Rabbaniha]

---------- Forwarded message ----------
From: Mahnaz Rabbaniha <rab.mahnaz at gmail.com>
Date: Sat, 10 Dec 2011 08:31:10 +0330
Subject: Re: [R-sig-eco] help
To: Sarah Goslee <sarah.goslee at gmail.com>

 Dear Sarah


thank you for your attention,

I want to use PCA with supplementary variables due to correlation
between the independent factor such as salinity ,temperature... with
dependent variable ( fish larva ) therefore changed  dependent
variable with log(x+1) and tested normality with shapiro test but data
haven't changed and remained non normality then i decided to used the
nonparametric analysis MDS   and found its order from net but it
wasn't successfully and plot of matrix was empty.

my question is: for using the MDS have to need the special form of
excel ,


thanks

mahnaz


On 12/9/11, Sarah Goslee <sarah.goslee at gmail.com> wrote:
> Hi,
>
> On Fri, Dec 9, 2011 at 7:13 AM, Mahnaz Rabbaniha <rab.mahnaz at gmail.com>
> wrote:
>> Hi
>>
>> in my project i collected its data in excel sheet that i attached,data
>> were non normal then i transformed them and check the normality by
>> shapiro.test that it showed again non-normality therefore i decided
>> used the MDS analyses in r and download this site
>>  ( http://www.statmethods.net/advstats/mds.html)
>>
>> but i haven't done it,  i think  the main problem is the form of excel
>> matrix for doing it and also i want to know about different between
>>  CLASSICAL
>> MDS and isoMDS.
>
> We need to know more about what you're donig to be able to help with
> the excel matrix. What is the problem? How are you importing it into R?
>
> ?cmdscale
> library(MASS)
> ?isoMDS
>
> offers some information about the algorithms used in the two approaches,
> as well as many references for more information
>
> Briefly and simplistically, the difference has to do with whether the
> algorithm
> attempts to preserve actual dissimilarities or rank-order dissimilarities.
>
>> please help me because this method is new in iran
>>
>> Thanks in advance
>> --
>> *Mahnaz Rabbaniha*
>> *Senior expert of marine ecology *
>> *Iranian Fisheries Research Organization (IFRO) *
>> *P.O.Box: 14155-6116 , P.Code: 1411816618*
>> Tehran, IRAN
>> Phone:   +98 21 44580953
>> *Fax:       +98 21 44580583*
>> *Mobile:  +98 912 5790377*
>> *Website: http://www.ifro.ir*
>>
>
> --
> Sarah Goslee
> http://www.functionaldiversity.org
>