topic PROC GLM: effects coding? in Statistical Procedures

PROC GLM: effects coding?

Ruth — Sat, 12 Nov 2011 09:35:01 GMT

Hi chaps,

I am running an analysis of multiple linear regression using PROC GLM, with the dataset mainly consisting of categorcial variables.

Do you know that if PROC GLM has the effects coding (-1, 0, 1) for the design matrix. As compared to the dummy coding (0, 1), the effects coding offers the advantage of comparing between each category and the grand mean.

Thanks in advance.

PROC GLM: effects coding?

Rick_SAS — Sat, 12 Nov 2011 19:45:21 GMT

For everything about effect coding in SAS, see http://support.sas.com/documentation/cdl/en/statug/63962/HTML/default/viewer.htm#statug_introcom_a0000003327.htm

GLM doesn't have the coding you want, but GENMOD does, and can do GLM-type models.

Or you can use the OUTDESIGNONLY OUTDESIGN= option in PROC LOGISTIC to output dummy variables for the explanatory variables, and this use those dummy variables in GLM. (Use anything for the response variable, like a constant vector.)

Rick

PROC GLM: effects coding?

Ruth — Mon, 14 Nov 2011 01:16:29 GMT

Thanks