Date:         Wed, 28 Sep 2005 14:13:43 -0400
Reply-To:     Art@DrKendall.org
Sender:       "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From:         Art Kendall <Art@DrKendall.org>
Organization: Social Research Consultants
Subject:      Re: 2nd Attempt: Grouping Zip Codes
Comments: To: Deepak Jethwani <deepak.jethwani@gmail.com>
In-Reply-To:  <2084e73d05092106191927dad6@mail.gmail.com>
Content-type: text/plain; charset=ISO-8859-1; format=flowed

Be aware that clusters could be very "stringy".

One approach would be to array the zips horizontally by longitude and
vertically by latitude of their centers.
If SPSS is the only tool you have, you can use FLIP and match cases by
zip followed by sort.
create a new set of string variables that are blank if the time is GT 10.
Print the data matrix as a  "map" and eyeball groupings.

Art
Art@DrKendall.org
Social Research Consultants
University Park, MD  USA  Inside the Washington, DC beltway.
(301) 864-5570


Deepak Jethwani wrote:

>Hi Listers,
> This is my second mail to the list. I am still struggling with the
>following issue.
> We have a list of zip codes and a table that lists out the drive time
>distance from one zip code to the other in the following format.
>
>Zip1 Zip2 Zip3 .....
>Zip1 0 5 15
>Zip2 5 0 12
>Zip3 15 12 0
>Zip4
>
>
>
>Now, we need to group the zip codes which fall within 10 minutes of drive
>time distance from a zip code into a group.
> The problem is actually about identifying starting zip codes around which
>to build these groupings.
>
>I would really welcome any comments from anyone who has faced a similar
>problem or any suggested approaches that come to mind for a possible
>solution or any suggested texts which I can use to tackle this problem.
>
>Best regards
> Deepak Jethwani
>
>
>
>