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pythonarraysnumpyrandomprobability

Generate list of numbers from a list with probability weights

How would one go about generating a list of random numbers from a list of 35 numbers with given probabilities:

Probability of number in range (1,5) - p1 = 0.5

Probability of number in range (6,15) - p2 = 0.25

Probability of number in range (16,35) - p3 = 0.25

I tried using numpy.random.choice() but I have no idea how to jam in possible lists of numbers.

Solution

  • If you want to select uniformly from each group:

    p=np.array([0.5/5]*5+[0.25/30]*30)
np.random.choice(np.arange(1,36),p=p/p.sum())

    UPDATE:

    and if you would like to select a list of random numbers (you can also set with or without replacement flag):

    np.random.choice(np.arange(1,36), size=N, replace=True, p=p/p.sum())