Use matplotlib to plot scatter point graph for a list of ascii data from standard input

plot_ascii.py

#!/bin/env python

import matplotlib.pyplot as plt
import getopt
import sys


try:
    opts, args = getopt.getopt(sys.argv[1:], 'x:y:')
except:
    print >>sys.stderr, "Argument error."
    sys.exit(1)

# set default xlabel and y label
xlabel = 'x'
ylabel = 'y'

for option, arg in opts:
    if option == '-x':
        xlabel = arg
    elif option == '-y':
        ylabel = arg

xes = []
yes = []

for line in sys.stdin:
    splited_line = line.split()

    x = float(splited_line[0])
    y = float(splited_line[1])

    xes.append(x)
    yes.append(y)


plt.plot(xes, yes, 'ro')

plt.xlabel(xlabel)
plt.ylabel(ylabel)
plt.show()