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...
In-Reply-To:  <1176924248.925438.136550@p77g2000hsh.googlegroups.com>
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
> more.
> "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?

Kevin Viel
PhD Candidate
Department of Epidemiology
Rollins School of Public Health
Emory University
Atlanta, GA 30322