calc Authority and Hub by HITS algorithm

hits.py

import numpy as np

graph = np.array([[0, 1, 0, 0], [1, 0, 1, 0], [1, 0, 0, 1], [0, 1, 0, 0]])

size = len(graph)
a = np.full((size, 1), 1.0 / size)
h = np.full((size, 1), 1.0 / size)

iter_cnt = 3
for i in range(iter_cnt):
    prev_a = a
    prev_h = h
    a = np.dot(graph, prev_h)
    a = a * (1 / np.sum(a))

    h = np.dot(graph.T, prev_a)
    h = h * (1 / np.sum(h))
    print('iter {}\n---'.format(i))
    print('a: {}\nh: {}\n'.format(a, h))