/*-----------------------------------------------------------------
S A S S A M P L E L I B R A R Y
NAME: CATEX3
TITLE: Example 3 for PROC CATMOD
PRODUCT: STAT
SYSTEM: ALL
KEYS: categorical data analysis
PROCS: CATMOD
DATA:
SUPPORT: Bob Derr
REF: SAS/STAT User's Guide, PROC CATMOD chapter
MISC:
-----------------------------------------------------------------*/
/*----------------------------------------------------------------
Example 3: Logistic Regression, Standard Response Function
Maximum Likelihood Logistic Regression
--------------------------------------
Ingots prepared with different heating and soaking times are
tested for readiness to roll.
From: Cox (1970, 67-68).
----------------------------------------------------------------*/
data ingots;
input Heat Soak nready ntotal @@;
Count=nready;
Y=1;
output;
Count=ntotal-nready;
Y=0;
output;
drop nready ntotal;
datalines;
7 1.0 0 10 14 1.0 0 31 27 1.0 1 56 51 1.0 3 13
7 1.7 0 17 14 1.7 0 43 27 1.7 4 44 51 1.7 0 1
7 2.2 0 7 14 2.2 2 33 27 2.2 0 21 51 2.2 0 1
7 2.8 0 12 14 2.8 0 31 27 2.8 1 22 51 4.0 0 1
7 4.0 0 9 14 4.0 0 19 27 4.0 1 16
;
title 'Maximum Likelihood Logistic Regression';
proc catmod data=ingots;
weight Count;
direct Heat Soak;
model Y=Heat Soak / freq covb corrb itprint design;
quit;