Date: Fri, 8 Aug 2008 09:26:10 -0400
Reply-To: "Keintz, H. Mark" <mkeintz@WHARTON.UPENN.EDU>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: "Keintz, H. Mark" <mkeintz@WHARTON.UPENN.EDU>
Subject: Re: What does "Interactivity disabled with BY processing" mean?
Content-Type: text/plain; charset="us-ascii"
DU820531 asked about a message from PROC REG:
> -----Original Message-----
> From: SAS(r) Discussion [mailto:SAS-L@LISTSERV.UGA.EDU] On Behalf Of
> Sent: Thursday, August 07, 2008 7:55 PM
> To: SAS-L@LISTSERV.UGA.EDU
> Subject: What does "Interactivity disabled with BY processing" mean?
> I am doing a rolling regression on a dataset with the following
> gvkey rollid year RET15 E_MV d_E_MV
> The output comes out but with a .log file that tells me following. I
> wonder whether the results are affected in some way and are they still
> usable. Thank you
> 25 ods listing close;
> 26 ods output ParameterEstimates=proj.valparest
> 26 ! FitStatistics=proj.valfit;
> 27 proc reg data=valdata;
> NOTE: The query requires remerging summary statistics back with the
> original data.
> 28 model RET15= E_MV d_E_MV;
> 29 by gvkey rollid;
> 30 run;
> NOTE: Interactivity disabled with BY processing.
> NOTE: PROCEDURE REG used (Total process time):
> real time 52.00 seconds
> cpu time 38.34 seconds
> NOTE: The data set PROJ.VALFIT has 82875 observations and 10
> NOTE: The data set PROJ.VALPAREST has 82875 observations and 10
Rest assured that this note does NOT refer to a
statistical property of your models, but to how
PROC REG can be used.
Ordinarily (without a BY statement) in PROC REG
you can "interactively" issue a sequence of
MODEL .. RUN code blocks. I.e., after seeing
the result of the first MODEL .. RUN, you can
spontaneously add/remove variables and issue a
second MODEL .. RUN. This works, because you
are still "interacting" with PROC REG (you need
a QUIT statement to exit the proc)
The benefit of this approach is that the second
MODEL .. RUN block doesn't generate a rereading
of the data. Instead it uses the SSCP matrix
produced by the first model, which is much faster.
(Note, if your first model uses only a subset of
vars you want in the SSCP matrix, then you need
to insert a VAR statement prior to the first
BUT ... when using a BY statement, the ability
to issue the second model statement is not
supported, presumably because PROC REG is not
able to maintain an SSCP matrix for each BY level.