[R] Smallest Space Analysis (SSA) in R

[Gasper Cankar]

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On Mon, Sep 24, 2018 at 3:18 PM +0200, "Andrew" <phaedrusv using gmail.com<mailto:phaedrusv using gmail.com>> wrote:


Ha! Even better - thank you. Plenty here for me to play around with.

Many thanks
Andrew


On 23/09/18 15:22, Michael Friendly wrote:
> On 9/22/2018 6:49 AM, Andrew wrote:
>> Hi Michael
>>
>> This looks like it could be really helpful in moving my project
>> forwards thank you.
>>
>> I remember many years ago using (proprietary) software from the
>> University of Liverpool which did a nice job of allowing regions to
>> be defined, and then for the space to be rotated to obtain visual
>> inspection of relative distance from different angles. I appreciate
>> that smacof will not do that, but as long as the analysis allows for
>> the graph to be plotted and analysed, that's what's important.
>
> You need not rely on the plots provided directly by a given package.
> Just roll your own using standard plotting libraries.
> Here is just the first Google hit on "R MDS 3D plot"
>
> http://omnilogia.blogspot.com/2014/05/basic-2d-3d-multi-dimensional-scaling.html
>
>
> which shows a rotating 3D plot, colored by a grouping variable. Here
> is another:
>
> http://whatzcookinlab.blogspot.com/2013/05/spinning-3d-mds-plot.html
>
> The vegan and ade4 packages also have a variety of plots and related
> methods.
>
>
> -Michael
>
>>
>> Thank you again, and to all of those who responded.
>>
>> Best wishes
>> Andrew
>>
>>
>> On 21/09/18 14:07, Michael Friendly wrote:
>>> Smallest space analysis (SSA) is just the name given to software
>>> developed by Guttman & Lingoes around the time the various versions
>>> of multidimensional scaling were being developed.  Call it Israeli MDS
>>> or Falafel MDS if you prefer. The reason you encountered it in your
>>> course is presumably that the instructor was trained in that.
>>>
>>> There are several variants of MDS-like algorithms for embedding
>>> points representing objects in a space, using data representing
>>> similarities or distances among objects -- metric (cmdscale)
>>> and non-metric (MASS::isoMDS), using only rank order information,
>>> and a variety of
>>> measures of goodness-of-fit ("stress").  I don't recall the details
>>> of the SSA programs, but that should matter little conceptually.
>>>
>>> The smacof package offers the widest array of possibilities.
>>>
>>> -Michael
>>>
>>>
>>> On 9/19/2018 7:00 AM, Andrew wrote:
>>>> Hi
>>>>
>>>> As part of my forensics psych course, we have been introduced to
>>>> Guttman's smallest space analysis (SSA). I want to explore this
>>>> approach
>>>> using R, but despite finding some queries on the web about this same
>>>> thing, have yet to find any answers. The MASS package doesn't seem
>>>> to do
>>>> the job, and the only thing I have been able to find is some
>>>> proprietary
>>>> software HUDAP  (Hebrew University Data Analysis Package) which
>>>> may/ not
>>>> be compatible with R (or GNU/Linux for that matter).
>>>>
>>>> Does anyone have information on how to do SSA using R?
>>>>
>>>> Many thanks
>>>>
>>>> Andrew
>>>>
>>>>
>>>>     [[alternative HTML version deleted]]
>>>>
>>>
>>>
>>
>
>

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