Hi:

Try the following for examples of the use of MDS in R:

http://www.statmethods.net/advstats/mds.html
http://cran.r-project.org/web/packages/HSAUR/vignettes/Ch_multidimensional_scaling.pdf
http://cran.r-project.org/web/packages/HSAUR2/vignettes/Ch_multidimensional_scaling.pdf
# (2nd ed.)
http://www.personality-project.org/R/mds.html
http://cran.r-project.org/web/packages/HSAUR2/vignettes/Ch_multidimensional_scaling.pdf
http://polisci.msu.edu/jacoby/icpsr/scaling/handouts/mds3/Nonmetric%20MDS,%202009%20Handout.pdf

Gotten by Googling 'multidimensional scaling R'...

HTH,
Dennis

On Mon, Feb 14, 2011 at 3:53 PM, Luca Turchet <turchet.luca@gmail.com>wrote:

> Hi Mike and all,
> thanks again. Actually your suggestion is a good way to print data in R,
> but
> unfortunately
> does not add any information to what I aready have on my table data.
>
> What I would like to see is how far are the trials from each others in
> terms
> of
> similarity.
>
> ...maybe I just need another way to analyze the data. For this reason I ask
> if someone has other suggestions, maybe coming back to the MDS?
>
> Is there anyone who can provide an R example about how I can analyze my
> data
> with a MDS analysis?
>
>
> Luca
>
>
>
> On Mon, Feb 14, 2011 at 6:40 PM, Mike Marchywka <marchywka@hotmail.com
> >wrote:
>
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > ________________________________
> > > Date: Mon, 14 Feb 2011 17:55:50 +0100
> > > Subject: Re: [R] Analyzing dissimilarity ratings with Multidimensional
> > > Scaling
> > > From: turchet.luca@gmail.com
> > > To: marchywka@hotmail.com
> > > CC: r-help@r-project.org
> > >
> > > Dear Mike,
> > > thanks a lot for your answer. Unfortunately the way you kindly
> > > suggested is not suitable
> > > to solve my problem.
> > >
> > > Indeed as said, I need to display the distances between the proposed
> > trials,
> > > for example I would like to see a 2D plot where I can see how fare is
> the
> > > trial MT-MT from the trial MT-SW (that is how far are the evaluations
> of
> > the
> > > audio-visual trial with metal-metal from the trial with metal-snow)
> >
> > I thought the dendrogram is what you wanted but apparently you can just
> > use daisy perhaps. This had a lot of typos and may not run as last
> example
> > I sent had bad edits but this does create scatterplot with zero points on
> > diagonal etc. Presumably you can define your own functions appropriate
> for
> > your data ( I've never used some of this before which is why I'm trying,
> > cavear emptor).
> >
> > library("cluster")
> > ddm<-daisy(matrix(xm,6,6),metric="euclidean")
> > str(ddm)
> > library("scatterplot3d")
> > dasm<-as.matrix(ddm);
> > nddf<-reshape(data.frame(dasm),varying=c("X1","X2","X3","X4","X5","X6"),
> > v.name="time", direction="long")
> > str(nddf)
> > ij<-as.numeric(gl(6,6))
> > n2<-cbind(nddf,ij)
> > str(n2)
> > scatterplot3d(n2$ij,n2$id,n2$time,type="h")
> >
> >
> >
> >
> > >
> > > Does anyone have any other suggestion to build such perceptual map in
> R?
> > >
> > > In addition, how can I get some information regarding the significant
> > > differences
> > > between the trials?
> > > If I used the ANOVA would be simple to get those p-values. I wonder if
> > > it is the
> > > case to use it...
> > >
> > > Help!
> > >
> > >
> > > Luca
> > >
> > >
> > >
> > >
> > > On Mon, Feb 14, 2011 at 3:23 PM, Mike Marchywka
> > > > wrote:
> > >
> > >
> > >
> > > > My first goal in the analysis process is to print a perceptual map
> > where to
> > > > place the pairs of
> > > > audio-visual stimuli (e.g. WD-WD, MT-DL, etc.) and see how far the
> > trials
> > > > are from each other.
> > >
> > > I've been using heatmap for stuff like this.
> > > You can get a nice picture this way and get quick visual
> > > survey and dendrograms,
> > >
> > > xm<-scan(file="avm.txt")
> > > str(xm)
> > > heatmap(xm)
> > > heatmap(matrix(xm,6,6))
> > >
> > > I ran the above on your data and it visually looks
> > > like there could be interesting patterns to test.
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > --
> > > ---------------------------------------------------------------
> > >
> > > "Music is a moral law:
> > > It gives a soul to the Universe,
> > > wings to the mind,
> > > flight to the imagination,
> > > a charm to sadness,
> > > and life to everything.
> > > It is the essence of order,
> > > and leads to all that is good,
> > > just and beautiful,
> > > of which it is the invisible,
> > > but nevertheless dazzling,
> > > passionate, and eternal form".
> > >
> > > Plato, 400 B.C. (from the Dialogues)
> > >
> >
> >
>
>
>
> --
> ---------------------------------------------------------------
>
> "Music is a moral law:
> It gives a soul to the Universe,
> wings to the mind,
> flight to the imagination,
> a charm to sadness,
> and life to everything.
> It is the essence of order,
> and leads to all that is good,
> just and beautiful,
> of which it is the invisible,
> but nevertheless dazzling,
> passionate, and eternal form".
>
> Plato, 400 B.C. (from the Dialogues)
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
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> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

	[[alternative HTML version deleted]]

