def removePtclsByLst(rejectlst, params):
	"""
	Removes particles by reading a list of particle numbers generated externally.

	Requirements:
		the input file has one particle per line
		the first piece of data is the particle number from the db
	"""
	f=open(params['rejectlst'],'r')
	lines=f.readlines()
	f.close()
	for n in lines:
		words = n.split()
		rejectlst.append(int(words[0]))
	return rejectlst