Find unique rows (submatrices) in a given matrix.

find_unique_rows.py

import numpy as np

# http://stackoverflow.com/questions/16970982/find-unique-rows-in-numpy-array

def find_unique_rows(array):
  b = array[np.lexsort(array.reshape((array.shape[0],-1)).T)];
  return b[np.concatenate(([True], np.any(b[1:]!=b[:-1], axis=tuple(range(1,array.ndim)))))]
  
  
if __name__ == "__main__":
  test_array = np.array([[0, 0],
                         [0, 1],
                         [1, 1],
                         [1, 1],
                         [0, 1],
                         [0, 0]])
  
  unique_elements = find_unique_rows(test_array)