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

For others looking for the answer in case of nd-array, as proposed by user holi:

my_array = np.random.rand(8, 50)
indices = np.random.choice(my_array.shape[1]*my_array.shape[0], replace=False, size=int(my_array.shape[1]*my_array.shape[0]*0.2))

We multiply the dimensions to get an array of length dim1*dim2, then we apply this indices to our array:

my_array[np.unravel_index(indices, my_array.shape)] = 0 

The array is now masked.