help

?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 , i have to use from ternsformed data,
I will be happy to provide any kind of solution

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*