new_contents: import numpy
  import pylab
  # Build a vector of 10000 normal deviates with variance 0.5^2 and mean 2
  mu, sigma = 2, 0.5
  v = numpy.random.normal(mu,sigma,10000)
  # Plot a normalized histogram with 50 bins
  pylab.hist(v, bins=50, normed=1)       # matplotlib version (plot)
  pylab.show()
  # Compute the histogram with numpy and then plot it
  (n, bins) = numpy.histogram(v, bins=50, normed=True)  # NumPy version (no plot)
  pylab.plot(.5*(bins[1:]+bins[:-1]), n)
  pylab.show()
  
subject: add hist