#Typical call is %'a:\stat519\sampwor' c1 c2 k1 c3 where c1 contains the
#numeric labels for each population element, c2 contains the
#sampling weights (often the size or approximate size of each sample point),
#k1 is the sample size and c3 is the output sample column.

macro
sampwor labcol sizecol nsamp samcol

mcolumn sizecol samcol labcol holdcol lab1col size1col
mconstant nsamp i samind

copy labcol lab1col
copy sizecol size1col
let size1col=size1col/sum(size1col)

do i=1:nsamp
 rand 1 holdcol;
 discrete lab1col size1col.
 let samind=holdcol
 copy size1col lab1col size1col lab1col;
 omit lab1col=samind.
 let size1col=size1col/sum(size1col)
 let samcol(i)=samind
enddo
endmacro