Date:         Thu, 11 Oct 2007 07:07:12 -0700
Reply-To:     rjs <rjstratton@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         rjs <rjstratton@GMAIL.COM>
Organization: http://groups.google.com
Subject:      problem getting var to randomize
Comments: To: sas-l@uga.edu
Content-Type: text/plain; charset="iso-8859-1"

Estimated G Matrix not positive definite
getting "." for the std error of some vars in the random statement
getting this error and not sure why
Some reasons I've been told
1 scaling of vars
          ran proc means and all vars are close to the same scale
2 vars could be linear combination of each other
          ran model with proc reg and the highest VIF is about 2.3
3 model contains binary vars
          of 4 binary vars only one is giving the "." error

running model with 100 classes 30 vars and about 100 obs per class
           get the error
ran the same model with only 12 classes
           get all vars to randomize

please any help is greatly appreciated