samplist_function(popn,sampsize){
# Samplist generates all possible SRS's of size sampsize
# from the population in vector popn.
# Auxiliary function:  comblist
# Returns:  matrix in which each row is one of the SRS's
popvals_ 1:length(popn)
temp_comblist(popvals,sampsize)
matrix(popn[t(temp)],nrow=nrow(temp),byrow=T)
}

comblist_function(popvals, sampsize)
{
# Comblist generates all combinations of the integers 1 through n,
# which are assumed to be the argument in popvals.
	popsize <- length(popvals)
	if(sampsize > popsize)
		stop("sample size cannot exceed population size")
	nvals <- popsize - sampsize + 1
	nrows <- prod((popsize - sampsize + 1):popsize)/prod(1:sampsize)
	ncols <- sampsize
	yy <- matrix(nrow = nrows, ncol = ncols)
	if(sampsize == 1) {
		yy <- popvals
	}
	else {
		nvals <- popsize - sampsize + 1
		nrows <- prod(nvals:popsize)/prod(1:sampsize)
		ncols <- sampsize
		yy <- matrix(nrow = nrows, ncol = ncols)
		rep1 <- rep(1, nvals)
		if(nvals > 1) {
			for(i in 2:nvals)
				rep1[i] <- (rep1[i - 1] * (sampsize + i - 
				  2))/(i - 1)
		}
		rep1 <- rev(rep1)
		yy[, 1] <- rep(popvals[1:nvals], rep1)
		for(i in 1:nvals) {
			yy[yy[, 1] == popvals[i], 2:ncols] <- Recall(
				popvals[(i + 1):popsize], sampsize - 1)
		}
	}
	yy
}