Dear Dick,
 
The following should work :
1) Perimeter area1 : P1, area2 : P2 
2) Combine area1 and area2 : perimeter : P12
3) The length of common intersection is : (P1 + P2 - P12) / 2
 
Kind regards,
 
Ton Brouwer
-----Original Message-----
From: Dick Hoskins <[EMAIL PROTECTED]>
To: WHO GIS <[EMAIL PROTECTED]>; [EMAIL PROTECTED] <[EMAIL PROTECTED]>; WAPHGIS <[EMAIL PROTECTED]>
Date: Monday, November 29, 1999 18:34
Subject: MI Common perimeter percentage

Couldn't get anyone to bite on this, try again:
 
In MapInfo suppose I have a coverage of Zipcodes (postcodes) I need to produce a table that tells me the 1,2,3,4,5 order nearest neighbors, the intercentroid distances, and for the 1st order nearest neighbors, the length of the common perimeter of neighbors, and the percentage of the perimeter.
 
I think I can figure out the nearest neighbor part, and the various orders of nearest neighbors, but getting the percentage or length of the common perimeter is evading me. Has occurred to me that it might be best to work with a MIF file, but its not clear (to me) how that is structured.
 
I am looking for a general way to proceed. MapInfo has a distance function and a perimeter function.
 
This is to be done in order to build a GLM for spatial autocorrelation of disease incidence.
 
Thanks
 
Dick Hoskins
[EMAIL PROTECTED]

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