Plot beta distribution, parameters a and b are provided via cmd line.

beta.py

import sys
import scipy as sp
from scipy.special import gamma
import pylab


a = float(sys.argv[1])
b = float(sys.argv[2])


def pdf(a, b, x):
    Z = gamma(a + b) / gamma(a) / gamma(b)
    return x**(a - 1) * (1 - x)**(b - 1) * Z


x = sp.arange(0, 1.01, 0.01)
y = pdf(a, b, x)
ax = pylab.subplot(111)
ax.plot(x, y, 'r', lw=2)
ax.set_xticks([0, 0.5, 1])
ax.set_xticklabels(['0', '0.5', '1'])
ax.set_yticks([0, 1, 2, 3])
ax.set_yticklabels(['0', '1', '2', '3'])
ax.set_xlabel(r'$\theta$', fontsize=18)
pylab.show()