scipy tutorial - Baustatik-Info-Server

SciPy Reference Guide, Release 0.8.dev
Display frozen pmf:
>>> rv = zipf(a)
>>> x = np.arange(0,np.min(rv.dist.b,3)+1)
>>> h = plt.plot(x,rv.pmf(x))
Check accuracy of cdf and ppf:
>>> prb = zipf.cdf(x,a)
>>> h = plt.semilogy(np.abs(x-zipf.ppf(prb,a))+1e-20)
Random number generation:
>>> R = zipf.rvs(a,size=100)
Custom made discrete distribution:
>>> vals = [arange(7),(0.1,0.2,0.3,0.1,0.1,0.1,0.1)]
>>> custm = rv_discrete(name=’custm’,values=vals)
>>> h = plt.plot(vals[0],custm.pmf(vals[0]))
Zipf distribution
zipf.pmf(k,a) = 1/(zeta(a)*k**a) for k >= 1
634 Chapter 3. Reference