Date: Wed, 11 Oct 2006 06:05:25 -0400
Reply-To: Peter Flom <flom@NDRI.ORG>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: Peter Flom <flom@NDRI.ORG>
Subject: Re: Hypergeometric distribution
Content-Type: text/plain; charset=US-ASCII
>>> <c_kenaszchuk@YAHOO.CA> 10/10/06 8:57 PM >>> wrote
Anyone familiar with Zelterman book, "Advanced Log-Linear Models Using
SAS"? I'm looking for help with Program 8.2 from the book. This program
fits a model to a stratified 2x2 table with the hypergeometric
distribution, and Prof. Zelterman's macros appearing in Program 8.4.
I have it, and have read it (I thought it quite good) but I don't have
Others may not have it at all. Why not post the code here?
I'm attempting to use the published programs to estimate the model.
Basic problem is that the model fails to converge. No problem with the
code; it's copied and pasted correctly from the SAS companion web site
into my data editor. It runs correctly with the supplied sample data. I
suspect a problem with my data and, probably, the appropriateness of
this model for my data. Error message in the log are these:
WARNING: The specified model did not converge.
ERROR: Error in computing the link function, its derivatives, or the
NOTE: The scale parameter was held fixed.
ERROR: Negative variance from user-defined variance function.ERROR:
Well, without knowing anything about your data, and without the program
to look at,
how can we tell? Clearly, the program doesn't work for you data, beyond
The scale parameter being fixed.......well......it MIGHT mean you need
to consider some other
distribution.....but it's really hard to say. One thing you might want
to look at it is the iterations history.
Why don't you write back to SAS-L, not just pasting in the code, but
describing your data,
how many variables, their nature, is it a survey or observational study
or what? What are you investigating?
What is sample size?
Then someone here may be able to help you