[R] Kruskal's MDS results

Dieter Vanderelst Dieter.Vanderelst at ua.ac.be
Fri Apr 17 09:55:12 CEST 2009


A few people suggested taking a look at Ripley's book MASS. I know the formula listed there.

The point is that the manual for the isoMDS function says it's stress output is in "percent". Does this mean, the stress reported by isoMDS is just the stress value in MASS (which ranges from 0 to 1) value multiplied by 100? I've haven't been able to find any resource that expresses stress in values from 0 to 100. So, this would be a convention introduced by the authors of the package?

In general, I think the R manuals could do with a bit more explaining on the output of the functions. I understand that some knowledge of statistics is assumed when working with R but sometimes the documentation on the returned values is really sparse. Even when familiar with the domain, there are several different conventions followed by different authors. This should be clear when reading the manual.

I know a lot of hard work gets into writing software, but it seems sometimes people are less keen on documenting their hard work properly.

stephen sefick wrote:
> You can look in MASS 4 for this formula on page 308 .  Go to the
> source and ask the horse he'll give you an answer that you endorse.
> 
> On Thu, Apr 16, 2009 at 8:13 AM, Bob Green <bgreen at dyson.brisnet.org.au> wrote:
>> Dieter,
>>
>> You could always try the "Classification, clustering, and phylogeny
>> estimation"  list which often includes posts regarding MDS:
>> http://lists.sunysb.edu/index.cgi?A0=CLASS-L
>>
>> regards
>>
>> Bob
>>
>> ______________________________________________
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>> and provide commented, minimal, self-contained, reproducible code.
>>
> 
> 
>




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