weight variable

[Geo-]

How to understand weight variable here?what is it for?redm_flag=0 means negative samples.

proc surveyselect  data=lg.develop_original(where=( redm_flag =0)) noprint
method=srs rate=0.1  out=lg.develop_sury ;
run;
data lg.develop_final;
set lg.develop_ original(where=( redm_flag =1)) lg.develop_sury;
if redm_flag=1 then weight=1;
else weight=10;
run;
proc freq data= lg.develop_final;
weight weight;
table redm_flag/missing;
run;

[Rick_SAS · Accepted solution]

The first proceu\dure extracts 1/10th of the observations where redm_flag=0. Each observation gets a weight of 10 to indicate that it represents 10 observations.

The DATA step merges that sample with all observations where redm_flag=1. Those observations get a weight of 1 to indicate that they represent 1 obs.

The PROC FREQ step estimates the proportions from the weighted sample.