Presenting Euclidean Distances

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Presenting Euclidean Distances

Adam Troy
Hi all,  

I have a table of Euclidean Distances for 100 cases (a 100 x 100 table) which I computed using PROXIMITIES. I am looking to present this data visually to identify any clusters of cases that represent groups of similar cases.  

Is there a preferred method of presenting a visual map of this data that can be implemented with SPSS 20?  

Thanks,

Adam Troy
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Re: Presenting Euclidean Distances

Zuluaga, Juan
I may not be understanding the question - what is wrong with Multidimensional scaling plots (PROXSCAL) or with dendrograms?

"I have a table of Euclidean Distances for 100 cases (a 100 x 100 table) which I computed using PROXIMITIES. I am looking to present this data visually to identify any clusters of cases that represent groups of similar cases.

Is there a preferred method of presenting a visual map of this data that can be implemented with SPSS 20?"

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Re: Presenting Euclidean Distances

David Marso
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In reply to this post by Adam Troy
Nobody wants to stare at a 100x100 table .  Even if such a person existed the table would be uninterpretable.   Natural ways of presenting such would be through a dendogram (see CLUSTER command which reads the previously generated distance matrix created in PROXIMITIES ).  I believe you can also get plots through MDS (ALSCAL) but I have not used that in some time.  Depending upon the nature of the data, correspondence analysis might provide additional insights.
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Adam B. Troy-3 wrote
Hi all,

I have a table of Euclidean Distances for 100 cases (a 100 x 100 table)
which I computed using PROXIMITIES. I am looking to present this data
visually to identify any clusters of cases that represent groups of similar
cases.

Is there a preferred method of presenting a visual map of this data that
can be implemented with SPSS 20?

Thanks,

Adam Troy
Please reply to the list and not to my personal email.
Those desiring my consulting or training services please feel free to email me.
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Cum es damnatorum possederunt porcos iens ut salire off sanguinum cliff in abyssum?"
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Re: Presenting Euclidean Distances

Art Kendall
In reply to this post by Adam Troy
The answer to that question depends to some degree on the nature of your data and who your audience(s) are.

What constitutes a case? I.e., what are the distances between?

What are the dimensions (variables usually) that went into the distances?  What were they? How were they chosen? How many are they?

Why did you choose Euclidean distance?  Is there a reason to assume that the dimensions are pretty much uncorrelated?

Do you expect to find a tree structure? Or are you looking to construct a single nominal level variable whose levels are the clusters?


Art Kendall
Social Research Consultants
On 7/16/2012 11:08 AM, Adam Troy wrote:
Hi all,  

I have a table of Euclidean Distances for 100 cases (a 100 x 100 table) which I computed using PROXIMITIES. I am looking to present this data visually to identify any clusters of cases that represent groups of similar cases.  

Is there a preferred method of presenting a visual map of this data that can be implemented with SPSS 20?  

Thanks,

Adam Troy


===================== To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD
Art Kendall
Social Research Consultants
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Re: Presenting Euclidean Distances

Adam Troy
Thanks everyone. On further investigation it looks like multidimensional scaling works quite nicely for this purpose.

Adam

On Wed, Jul 18, 2012 at 7:54 AM, Art Kendall <[hidden email]> wrote:
The answer to that question depends to some degree on the nature of your data and who your audience(s) are.

What constitutes a case? I.e., what are the distances between?

What are the dimensions (variables usually) that went into the distances?  What were they? How were they chosen? How many are they?

Why did you choose Euclidean distance?  Is there a reason to assume that the dimensions are pretty much uncorrelated?

Do you expect to find a tree structure? Or are you looking to construct a single nominal level variable whose levels are the clusters?


Art Kendall
Social Research Consultants
On 7/16/2012 11:08 AM, Adam Troy wrote:
Hi all,  

I have a table of Euclidean Distances for 100 cases (a 100 x 100 table) which I computed using PROXIMITIES. I am looking to present this data visually to identify any clusters of cases that represent groups of similar cases.  

Is there a preferred method of presenting a visual map of this data that can be implemented with SPSS 20?  

Thanks,

Adam Troy