How to make a checkerboard in numpy?

Question

I\'m using numpy to initialize a pixel array to a gray checkerboard (the classic representation for \"no pixels\", or transparent). It seems like there ought to be a whizzy

Answer 1

I'm not sure if this is better than what I had:

c = numpy.fromfunction(lambda x,y: ((x//sq) + (y//sq)) % 2, (w,h))
self.chex = numpy.array((w,h,3))
self.chex[c == 0] = (0xAA, 0xAA, 0xAA)
self.chex[c == 1] = (0x99, 0x99, 0x99)

Answer 2

import numpy as np
b = np.array([[0,1],[1,0]])

Replace n with a even numberand you will get the answer. Easy right?

np.tile(b,(n, n))

Answer 3

import numpy as np
n = int(input())
arr = ([0, 1], [1,0])
print(np.tile(arr, (n//2,n//2)))

For input 6, output:

   [[0 1 0 1 0 1]
    [1 0 1 0 1 0]
    [0 1 0 1 0 1]
    [1 0 1 0 1 0]
    [0 1 0 1 0 1]
    [1 0 1 0 1 0]]

Answer 4

Suppose we need a patter with length and breadth (even number) as l, b.

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

As this base matrix, which would be used as a tile already has length and breadth of 2 X 2, we would need to divide by 2.

print np.tile(base_matrix, (l / 2, b / 2))

print (np.tile(base,(4/2,6/2)))
[[0 1 0 1 0 1]
 [1 0 1 0 1 0]
 [0 1 0 1 0 1]
 [1 0 1 0 1 0]]

Answer 5

Simplest implementation of the same.

import numpy as np

n = int(input())
checkerboard = np.tile(np.array([[0,1],[1,0]]), (n//2, n//2))
print(checkerboard)

Answer 6

Numpy's Tile function to get checkerboard array of size n*n

import numpy

n = 4

list_0_1 = [ [ 0, 1], [ 1, 0] ]

checkerboard = numpy.tile( list_0_1, ( n//2, n//2) ) 

print( checkerboard)

[[0 1 0 1]
 [1 0 1 0]
 [0 1 0 1]
 [1 0 1 0]]