07-13-2012 09:14 AM
I am working on a project where we need to sample some items in a warehouse with the higher dollar items having a higher chance of being picked. When I ran the data through PROC SURVEYSELECT METHOD=PPS I get the following error "the relatize size of each sampling unit must not exceed 1/sampsize.
If I redued the sample size to 7 this error goes away, unfortunately I need a sample size of 37.
After soon searching, i found some posts on SAS-L and sas.support to find the maximum sample use that stop this problem from happening or to use the MINSIZE, MAXSIZE, CERTSIZE options. By toying with the CERTSIZE I got it to work, but the logic behind the MINSIZE and MAXSIZE escape me.
I created a test data set that is fairly representitive of what my inventory data looks like. For some reason I can't paste my code in here so I hope I make no typos
do id=1 to 183;
if id le 1 then value=id;
* this outputs as error;
proc surveyselect data=one method=pps seed=6845 n=37 out=sample_one;
By using n=20 the error goes away;
Any guidance on using MINSIZE or MAXSIZE would be appreciated.