01-30-2016 01:04 PM
I would like to ask if there is a way to specify not only the initial seed number, but a seed for each replication when using replicate in PROC surveyselect?
The background of my question is, I want to compare two ways to do 2-stage-sampling in PROC survey select, one using replicate and one using loops. The latter results should be correct, so I have a benchmark. But as both procedures (hopefully) do the same things in different order, I cannot compare them properly with only the initial seed number. Without controlling for subsequent draws, I cannot decide if different results stem from random influences or if there is some systematic difference (i.e. some mistake).
PS. I had problems in sending this message, so I hope there was not double posting.
Thanks for your help
01-30-2016 05:14 PM
You can get initial seeds for each stratum in stratified sampling but not for each replicate in replicated sampling. So, simulate the later with the former.
data c; set sashelp.class; do rep = 1 to 10; output; end; run; proc sort data=c; by rep; run; proc surveyselect data=c out=samples seed=12345 outseed sampsize=12; strata rep; run; ; data _null_; do until(last.rep); set samples; by rep; end; call execute(catt( "proc surveyselect data=sashelp.class out=s sampsize=12 seed=", initialSeed, "; run; proc append base=sample2 data=s; run;")); run;
Samples (pseudo replicated samples) and Sample2 (samples from a loop) are the same.
01-31-2016 03:36 AM