# -*- coding: utf-8 -*- """ Created on Tue Oct 4 17:10:17 2016 @author: dlivelyb """ # roll your own array of pointers (ngcgalx: into previously # read array galaxies) into rows with galaxies named NGC* ngcgalx = [] ngcptr = [] j = 0 for i in galaxies: if i[:2] == "NGC": ngcgalx += [i] # ngcgalx is name of ngc galaxy ngcptr += [j] # ngcptr is the actual pointer j = j+1 # use pointer to point (arf!) Assumes a column of data from # file that is named HRV. This will pick out only NGC data HRVngc = [HRV[el] for el in ngcptr]