topic Re: INITIAL option and BY statements in GENMOD procedure in Statistical Procedures

INTERCEPT option and BY statements in GENMOD procedure

Fri, 29 Jan 2010 12:41:56 GMT

I'm using the BY statement to have split calculations for various groups in the same dataset, but when I specify initial values for the intercept estimate in PROC GENMOD (INTERCEPT option to the MODEL statement), only the first of the BY-groups uses the initial value. Is there any way to give an initial value for each BY-group?

Edit: Confused INITIAL and INTERCEPT options in original post. Message was edited by: T

Re: INITIAL option and BY statements in GENMOD procedure

Dale — Fri, 29 Jan 2010 20:08:54 GMT

Good question! It does not appear to me that it is possible to initialize the intercept for any but the first by group - unless you specify the NOINT option. Specifying an intercept along with the NOINT option would fix an intercept at the specified value (which, I believe, is probably not what you want).

I would report this to SI as a bug and see what they say.

Re: INITIAL option and BY statements in GENMOD procedure

Wed, 03 Feb 2010 10:56:18 GMT

I've reported to the SAS Support now, so we'll see if they have a solution. Thanks for your reply.

Re: INITIAL option and BY statements in GENMOD procedure

Mon, 08 Feb 2010 15:14:40 GMT

Hi again,

I had a reply from the SAS Support. Apparently this is a known limitation with GENMOD, which they hope to fix in the next version.

Until then, I guess the WHERE statement is an acceptable work-around.