Date: Wed, 18 Apr 2007 15:41:23 -0400
Reply-To: Kevin Roland Viel <kviel@EMORY.EDU>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: Kevin Roland Viel <kviel@EMORY.EDU>
Subject: Re: old version of proc logistic mystery...
Content-Type: TEXT/PLAIN; charset=US-ASCII
On Wed, 18 Apr 2007, z wrote:
> OK, I got handed a piece of code that used to work and doesn't any
> "What did you change?"
> "Nothing, honest!!"
> After much, I discover that what "used to work" was:
> 1) using proc logistic to model an outcome and generate a set of
> parameter estimates, years ago;
> 2) every quarter since, feeding proc logistic with that same model
> that pre-estimated set of parameters from step 1, using inest=; giving
> it a dataset of current values for the model input variables but with
> the outcome variable always = 0; and having it just calculate
> predicted values for the outcome for each observation from the model
> using the parameter estimates file and the current model input
> variables in the dataset, without doing any actual model fitting since
> the outcome value is always 0 in the new dataset.
> That doesn't work now, proc logistic just complains that there is no
> variation in the modeled otucome and quits without calculating any
> predictions. (SAS 9.1.3, UNIX)
> I have a workaround that's fine, I don't need any fixes; but, they
> insist that it used to work and SAS disagrees that it would ever work,
> with any version. For my own random curiosity, (and future SAS trivia
> bowls), does anybody actually know of any version of SAS where proc
> logistic would crank through one iteration before quitting, when the
> modeled variable had no variation, as in the above?
No, but could you post the code?
Department of Epidemiology
Rollins School of Public Health
Atlanta, GA 30322