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Date:         Wed, 23 Jun 2010 14:10:28 -0700
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Mary <mlhoward@AVALON.NET>
Subject:      Re: proc mixed levels, one level missing
Comments: To: Arthur Westover <anwestover@SBCGLOBAL.NET>
Content-Type: text/plain; charset="UTF-8"

Given that it is one less, one suspect cause might be the way it is creating dummy variables between the two procedures; in logistic it will create the same number of dummy variables as classes (which wasn't the way I was taught in school), and to get the reference coding you need to specifically say that you want it, like this:

proc logistic.. class period(param=ref ref='basevalue');

Where you put in the value of the base value. I'm not sure about how mixed does the reference coding, but perhaps that is the difference; it might not hurt to try it out.


--- anwestover@SBCGLOBAL.NET wrote:

From: Arthur Westover <anwestover@SBCGLOBAL.NET> To: SAS-L@LISTSERV.UGA.EDU Subject: proc mixed levels, one level missing Date: Wed, 23 Jun 2010 11:30:33 -0700

I am running a proc mixed procedure. I have a variable 'period' that has 10 different values. I have confirmed this using proc freq.

When I run proc mixed, I only have 9 levels for the variable 'period.' The number of levels for the other variables appear to be correct.

When I try using proc logistic, and throw in 'period', there are 10 levels. I don't know what the problem is.

Here is my proc mixed statement:

PROC MIXED data= big2 order=data; CLASS period VarC VarD VarE VarF VarG VarH; MODEL sysbp= VarA VarB VarE VarH VarF VarI VarJ cpd pilus VarC|VarG|period/ ddfm=kr(firstorder); repeated / type=ar(1) sub=VarD(VarC); lsmeans VarC VarE VarG VarF/ cl diff;

lsmeans VarC*period*VarG / diff cl slice=(period VarC VarG); lsmeans VarC*VarG / diff cl slice=(VarC VarG); lsmeans VarC*period / diff cl slice=(VarC period); lsmeans VarG*period / diff cl slice=(VarG period); lsmeans period / cl diff; run;

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