Generate array of number pairs from 2 numpy vectors [duplicate]

Question

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Cartesian product of x and y array points into single array of 2D points (16 answers)

Closed 8 years ago.

Is there an easy way in Numpy to generate an array of number pairs from 2 1D numpy arrays (vectors) without looping?

input:

a = [1, 2, 3]
b = [4, 5, 6]

output:

c = [(1,4), (1,5), (1,6), (2,4), (3,5), (2,6), (3,4), (3,5), (3,6)]

I wondering if there is a function that does something similar to this:

c = []
for i in range(len(a)):
    for j in range(len(b)):
        c.append((a[i], b[j]))

Answer 1

You can use itertools.product for this:

from itertools import product

c = list(product(a, b))

This gives:

c == [(1, 4), (1, 5), (1, 6), (2, 4), (2, 5), (2, 6), (3, 4), (3, 5), (3, 6)]