Date:         Fri, 25 Sep 1998 18:41:56 -0500
Reply-To:     Tae-Sung Shin <sts@STATSOFT.COM>
Sender:       "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
From:         Tae-Sung Shin <sts@STATSOFT.COM>
Subject:      Computation of Pearson residual in Logit Regression
Content-Type: text/plain; charset="us-ascii"

Hello SAS users,
 
This is simple question for logit regression.
 
Say we have the following data & program.
 
data aaa;
input var1 var2 var3;
cards;
23.840  1.000   4.000
22.690  1.000   5.000
24.770  1.000   17.000
25.840  1.000   21.000
26.790  1.000   15.000
27.740  1.000   20.000
28.670  1.000   15.000
30.410  1.000   14.000
22.690  0.000   9.000
23.840  0.000   10.000
24.770  0.000   11.000
25.840  0.000   18.000
26.790  0.000   7.000
27.740  0.000   4.000
28.670  0.000   3.000
30.410  0.000   0.000
proc logistic;
model var2=var1/influence;
freq var3;run;
 
proc logistic;
model var2=var1/influence;
weight var3;run;
 
As far as I know and as in SAS manual, above two procedure should
give us the same pearson & deviance residuals but it's not true.
It seems to me that's because weights are included in the computation
of the residuals, but frequencies are not...
Could anybody explain why? or is it a bug?
 
 
Thanks in advance.
 
Tae-Sung Shin