make CDF
There must be at least two elements in the supplied array. All elements must be probabilities within 0.0, 1.0. The sum of the probabilities must be 1.0
Return
a valid CDF
Parameters
prob
the array representing a PMF
There must be at least two elements in the supplied array. All elements must be probabilities within 0.0, 1.0. The sum of the probabilities must be 1.0
a valid CDF
the array representing a PMF