topic Re: Graphing continuous-continuous interaction for a specified range of x-axis in Graphics Programming

Graphing continuous-continuous interaction for a specified range of x-axis

Blain — Thu, 04 Apr 2019 03:44:38 GMT

I ran the following codes to graphically show the predicted probabilities of y (binary) vs. x1 (continuous) at different values of x2 (continuous).

proc logistic data=data;
   model y(event='1') = x1 | x2;
   store logiMod;
run;

title "Predicted probabilities";
proc plm source=logiMod;
   effectplot slicefit(x=x1 sliceby=x2=0 to 30 by 5);
run;

These codes give me the graph for the whole range of x1. But I want to show this graph for a specified range of x1 (say, for 0-20 with an increment of 2 for grids) without changing my main model. How can I get that? Can anyone demostrate any alternative way to produce a similar graph if such an option is not available in proc plm?

Re: Graphing continuous-continuous interaction for a specified range of x-axis

PGStats — Thu, 04 Apr 2019 04:44:01 GMT

For more flexibility, you could skip proc plm and do your own scoring. For example:

data heart;
set sashelp.heart;
alive = missing(ageAtDeath);
run;

data graphValues;
do smoking = 0, 10, 20, 30;
    do systolic = 120 to 180;
        output;
        end;
    end;
label 
    smoking="Cigarettes per day" 
    systolic="Systolic blood pressure";
run;

proc logistic data=heart;
model alive = systolic smoking;
score data=graphValues out=graphScores;
run;

proc sgplot data=graphScores;
series x=systolic y=p_0 / group=smoking lineattrs=(pattern=solid);
run;

Re: Graphing continuous-continuous interaction for a specified range of x-axis

Blain — Thu, 04 Apr 2019 18:28:50 GMT

Thanks!