[FIXED] Python random sample of two arrays, but matching indices

Issue

I have two numpy arrays x and y, which have length 10,000. I would like to plot a random subset of 1,000 entries of both x and y. Is there an easy way to use the lovely, compact random.sample(population, k) on both x and y to select the same corresponding indices? (The y and x vectors are linked by a function y(x) say.)

Thanks.

Solution

You can use np.random.choice on an index array and apply it to both arrays:

idx = np.random.choice(np.arange(len(x)), 1000, replace=False)
x_sample = x[idx]
y_sample = y[idx]

Answered By - Jaime