#!/usr/bin/env python
#Author: Shriphani Palakodety
#Mail: shriphani@shriphani.com
#Blog: http://shriphani.com/blog

#A plot of the Zeta function using Python + matplotlib

#import the required modules:

from pylab import *

def zetaValue(n):
    val = 0 #We got to start somewhere
    for i in range(1, n+1):
	zeta_term = float(1)/float(i**2)
	val += zeta_term
    return val


def makePlotRange():
    num_list = []
    range_list = []
    for i in xrange(1,1000):
	num_list.append(i)
	range_list.append(zetaValue(i))
    return num_list, range_list

plot_range = makePlotRange()

constant = [1.65] * len(plot_range[0])

#plot(t, zetaValue(t), 'r--', t, 1.69, 'bs')
plot(plot_range[0], plot_range[1], 'bs', plot_range[0], constant, 'r--')
savefig('zetaplot.png')
show()