Empirical logit plot between x and binary to check their linear relationship

** purpose: draw the expirical logit plot between x and binary y ;

** to check if there is linear relation or not                   ;

 

%macro empplot(indata, xvar, yvar);

 

proc rank data=&indata groups=100 out=out;

        var &xvar;

        ranks bin;

run;

 

proc means data=out noprint nway;

        class bin;

        var &yvar &xvar;

        output out=bins sum(&yvar)=&yvar mean(&xvar)=&xvar;

run;

 

data bins;

        set bins;

        elogit=log((&yvar+(sqrt(_freq_)/2))/(_freq_-&yvar+(sqrt(_freq_)/2)));

run;

 

proc sgplot data=bins;

        reg y=elogit x=&xvar / curvelabel="Linear Relationship?"

                curvelabelloc=outside

                lineattrs=(color=ligr);

        series y=elogit x=&xvar;

        title "Empirical Logit against &xvar";

run;

 

proc sgplot data=bins;

        reg y=elogit x=bin /

                curvelabel="Linear Relationship?"

                curvelabelloc=outside

                lineattrs=(color=ligr);

        series y=elogit x=bin;

        title "Empirical Logit against Binned &xvar";

run;

 

%mend empplot;

 

 

An example: from previous univariate screening it is showing there is relatively strong relation between recent_view_count and action. So we draw their expirical logit as below:

%empplot(dyps.dyps_trainoversamp2, recentview_count, action);