How to randomly set elements in numpy array to 0

Question

First I create my array

myarray = np.random.random_integers(0,10, size=20)

Then, I want to set 20% of the elements in the array to 0 (or some o

Answer 1

You can calculate the indices with np.random.choice, limiting the number of chosen indices to the percentage:

indices = np.random.choice(np.arange(myarray.size), replace=False,
                           size=int(myarray.size * 0.2))
myarray[indices] = 0