Date:         Sat, 22 May 1999 15:53:51 -0500
Reply-To:     Michael McQuestion <mcquesti@SSC.WISC.EDU>
Sender:       "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
Comments:     cc: Michael McQuestion <mcquesti@duncan.ssc.wisc.edu>
From:         Michael McQuestion <mcquesti@SSC.WISC.EDU>
Subject:      adjacency matrix
Comments: To: SAS-L@LISTSERV.VT.EDU
Content-Type: TEXT/PLAIN; charset=US-ASCII

Can anyone give me an idea how to use SAS to make an adjacency matrix?
This is an NxN matrix in which each cell is a weight representing
the distance from observation i to every other observation in the set.
 
I need this matrix in order to fit a spatial diffusion model.
 
Most values will be 0, those in adjacent regions might be weighted be 0.5,
those in adjacent towns .75, those in the same town 1.0.
 
Each row could then be standardized to sum to 1.
 
Any help will be appreciated.
 
Michael McQuestion
Center for Demography and Ecology
University of Wisconsin- Madison
1180 Observatory Drive
Madison, WI  53706
USA
 
phone: (608) 238 5458
fax: (608) 262 8400