问具有圆形距离的网格python

EN

import numpy as np

q = 6  # rows
p = 5  # columns

# Create array of indices
a = np.mgrid[0:q, 0:p].transpose(1, 2, 0)

# The array `a` now has shape (q, p, 2) :
a[1, 2]  # array([1, 2])
a[3, 0]  # array([3, 0])

# Create a new array measuring the i,j difference between all pairs of 
# locations in the array. `diff` will have shape (q, p, q, p, 2) :
diff = a[None, None, :, :, :] - a[:, :, None, None, :]

# Modify diff to obey circularity constraint
di = diff[..., 0]
dj = diff[..., 1]
di[di > q//2] -= q
dj[dj > p//2] -= p

# compute distance from diff
dist = (diff[..., 0]**2 + diff[..., 1]**2)**0.5

# test:
dist[1, 0, 1, 0]  #  0.0
dist[1, 0, 1, 1]  #  1.0
dist[1, 0, 1, 2]  #  2.0
dist[1, 0, 1, 3]  #  2.0
dist[1, 0, 1, 4]  #  1.0