Maptitude - http://research.umbc.edu/~roswell/maptitude.html Richard (and whoever else is interested), Peter helped me in February with another problem where Merge by Value was the solution (summarizing data by enclosing Zip Codes), as repeated below. You can check the archives for the whole thread. Steve Hendel [EMAIL PROTECTED] Office Depot Senior MIS Consultant --------------------------- Original question: >Is there a way, without external processing, that we can specify to have point >ZIP data mapped into the area ZIP in which the point ZIPs are enclosed? Tools-Merge by Value is more powerful than currently documented. You can take any table, designate a field to merge by, specify what to create from which fields (nothing, total, average, etc., or any combination), and save the results in a new table. So: 1. Join your table by ZIP Code to the point ZIP Code table. 2. Use Merge by Value on the enclosing ZIP Code field. 3. Specify the fields you want totaled (or whatever) in the new table. 4. Join the resulting table to the area ZIP Code layer, and start analyzing! Peter -----Original Message----- From: Health Maps [mailto:[EMAIL PROTECTED]] Sent: Wednesday, April 11, 2001 12:22 PM To: Maptitude Subject: RE: [Maptitude] Thematic Mapping Question Maptitude - http://research.umbc.edu/~roswell/maptitude.html I encourage some more discussion on the merge by value feature. I have never understood it - now I have a glimmer. This sounds like a very powerful feature. Richard Hoskins [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> GMT -8 -----Original Message----- From: Peter H. Van Demark [mailto:[EMAIL PROTECTED]] Sent: Wednesday, April 11, 2001 8:45 AM To: Maptitude Subject: Re: [Maptitude] Thematic Mapping Question Maptitude - http://research.umbc.edu/~roswell/maptitude.html All: I want to add to the previous answers another one that uses the Merge by Value command, which is under-documented (my fault). It is a great way to combine records that have a common value. Using Kjartan's formula field to merge records with the same lat/lon, and another formula field (Count is a good name) with 1 as its formula, you can merge on the first formula field, add the second formula field, and copy/add/whatever other fields to get your summary table. Then use Locate by Coordinate to turn the table into a point layer, and use the Count field for your theme(s). Peter ---------------------------------------------------------------- Peter Van Demark Director of GIS Products and Training Phone: 617-527-4700 Caliper Corporation Fax: 617-527-5113 1172 Beacon Street E-mail: [EMAIL PROTECTED] Newton MA 02461-9926 Web site: http://www.caliper.com ______________________________________________________________________ To unsubscribe, write to [EMAIL PROTECTED]
