Date: Wed, 21 Sep 2005 19:57:31 +0530
Reply-To: Deepak Jethwani <email@example.com>
Sender: "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From: Deepak Jethwani <firstname.lastname@example.org>
Subject: Re: 2nd Attempt: Grouping Zip Codes
Content-Type: text/plain; charset=ISO-8859-1
Thanx for your thoughts. My appologies for not explaining this in a better
An optimal partitioning in our case would be minimal number of groups of
these zip codes which should be ideally mutually exclusive.
I am not very sure I completely understand your heuristic algorithm
approach. How exactly does one go about programming the same (Can it be done
in SPSS ?)
On 9/21/05, Spousta Jan <JSpousta@csas.cz> wrote:
> Hi Deepak,
> Only a few thoughts:
> 1) Your problem is not specified enough - there can be a plenty of
> possible solutions - you should say what you consider to be an optimal
> partitioning of the ZIP codes. E.g. "the minimal number of clusters, and
> - if still many solutions possible - the minimal sum of diameters of
> 2) But I suspect that (at least for many reasonable specifications of
> the task) the problem will be extremely hard to solve exactly (many
> similar problems are proved to be NP-complete). So you will probably
> seek a quick and dirty heuristic algorithm.
> 3) The question is then, whether SPSS is just the best tool to create
> such algorithm - another possibility is to use a general programming
> language. It can be better suited to go through the data in logically
> complicated ways. (SPSS and similar tools use the top-to-bottom way
> automatically - they just read/write all cases in one step...)
> -----Original Message-----
> From: SPSSX(r) Discussion [mailto:SPSSX-L@LISTSERV.UGA.EDU] On Behalf Of
> Deepak Jethwani
> Sent: Wednesday, September 21, 2005 3:20 PM
> To: SPSSX-L@LISTSERV.UGA.EDU
> Subject: 2nd Attempt: Grouping Zip Codes
> 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
> 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