topic Re: Question about proc logistic and correlation between input vars in SAS Enterprise Guide

Question about proc logistic and correlation between input vars

juanvg1972 — Wed, 24 May 2017 17:43:22 GMT

Hi,

I have a question about proc logistic.
I am creating a regresion logistic model with proc logistic.

All the vars included in the model have dependencies with the target table.
Using proc freq or proc discrim I can see that there is a dependency

When I am exploring the vars, I find that there are vars highly correlated.
The vars rango_ant and rango_edad hace a correlation about 0.9

Do I have to exclude one of them from my model?

This is my model:

proc logistic data=test outmodel=modelo1 plots(only)=roc;
class cod_posicion nivel_sal rango_edad rango_ant rango_eval;
model baja = rango_edad rango_ant nivel_sal rango_eval cod_posicion ;
quit;

Do I have tu use cross effects?. Like this:

proc logistic data=test outmodel=modelo1 plots(only)=roc;
class cod_posicion nivel_sal rango_edad rango_ant rango_eval;
model baja = rango_edad rango_ant nivel_sal rango_eval cod_posicion rango_edad*rango_ant ;
quit;

proc logistic data=test outmodel=modelo1 plots(only)=roc;
class cod_posicion nivel_sal rango_edad rango_ant rango_eval;
model baja = rango_edad rango_ant nivel_sal rango_eval cod_posicion rango_edad*rango_ant ;
quit;

I don't know the effect of correlation in logistic regresion.
Can anybody help me?, any help will be greatly appreciated

Thanks in advance

Re: Question about proc logistic and correlation between input vars

TomKari — Wed, 24 May 2017 17:55:20 GMT

I suggest you post this in one of the Analytics communities. It really doesn't have anything to do with Enterprise Guide.

Tom

Re: Question about proc logistic and correlation between input vars

juanvg1972 — Wed, 24 May 2017 18:29:53 GMT

Ok, but proc logistic is a task of E.G.

Re: Question about proc logistic and correlation between input vars

TomKari — Wed, 24 May 2017 18:59:57 GMT

Technically, SAS EG has a task called "Logistic Regression". This task runs PROC LOGISTIC to do the calculations.

It's a little confusing, but here's how I'd describe the dividing line. If I had questions about the meanings of the variable roles or about some of the task options, I'd post under Enterprise Guide. But if a question pertains to the underlying PROC LOGISTIC code, as yours does, I think it's a better fit in the Analytics community. I'm an IT guy, and I monitor the EG community for technical questions about using the product, but I don't have the statistical methodology chops to answer questions like yours. Those guys are in the Analytics community.

Tom