def __init__(self, xk, pk):
""" Create a bit vector RV with the specified distribution.
Parameters:
-----------
xk : sequence of bit vectors
pk : sequence of floats
A sequence of bit vectors with corresponding probabilities. The bit
vectors must be of the same length l. Any bit vector of length l not
specified has zero probability.
"""
xk = np.array(xk, copy=0)
pk = np.array(pk, copy=0)
is_nonzero_p = (pk != 0)
xk, pk = xk[is_nonzero_p], pk[is_nonzero_p]
self.length = xk.shape[1]
self._table = dict(izip(bit_vector_to_str(xk), pk))
self._xk = xk
self._rv = rv_discrete(values=(np.arange(len(xk)), pk))
def pmf(self, xk):
""" The probability mass function evaluated for the given bit vector(s).
"""
return self._pmf(bit_vector_to_str(xk))
