CODEWITHSUNDEEP
saslogistic-regression
Maringo7
Maringo7

Reputation: 63

In PROC LOGISTIC which value of the parameter is modelled?

My colleague and I are running exactly the same SAS PROC LOGISTIC, but with different input files. SAS models ooX = 1 when I do it, and ooX = 0 when he does it. We've checked record counts and FREQ counts for the main variables. They are the same. Type 3 analysis of effects are the same. MLE estimates are the same, except for the intercept. Does SAS require input to be sorted a certain way? 

PROC LOGISTIC data = TTTT;
class ooX Y1 Y2 Y3 Y4;
model ooX = Y1 Y2 Y3 q1 q2 q3;
RUN;

Upvotes: 1

Views: 138

Answers (2)

Kostya
Kostya

Reputation: 1572

As explained in SAS manual (http://support.sas.com/documentation/cdl/en/statug/63347/HTML/default/viewer.htm#statug_logistic_sect030.htm)

For binary response data with event and nonevent categories, if your event category has a higher Ordered Value, then by default the nonevent is modeled.

Upvotes: 0

LJW
LJW

Reputation: 815

If your data are not sorted you can specify the order of your outcome variable right after calling PROC LOGISTIC.

I don't have the data, but assuming that ooX is a binary outcome variable with levels 0 and 1, the model will default to modeling ooX = 0 unless you specify that you want it in descending order.

PROC LOGISTIC data = TTTT descending; /* will model ooX = 1 */
class ooX Y1 Y2 Y3 Y4; /* Not sure if it makes sense to  have your outcome in the class statement */
model ooX = Y1 Y2 Y3 q1 q2 q3;
RUN;

Upvotes: 1

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