In [1]:

    

import numpy as np


    

In [2]:

    

a = np.arange(16).reshape(4, 4)
print(a)


    

    




[[ 0  1  2  3]
 [ 4  5  6  7]
 [ 8  9 10 11]
 [12 13 14 15]]

In [3]:

    

print(np.tril(a))


    

    




[[ 0  0  0  0]
 [ 4  5  0  0]
 [ 8  9 10  0]
 [12 13 14 15]]

In [4]:

    

print(np.tril(a, k=2))


    

    




[[ 0  1  2  0]
 [ 4  5  6  7]
 [ 8  9 10 11]
 [12 13 14 15]]

In [5]:

    

print(np.tril(a, k=-1))


    

    




[[ 0  0  0  0]
 [ 4  0  0  0]
 [ 8  9  0  0]
 [12 13 14  0]]

In [6]:

    

a = np.arange(12).reshape(3, 4)
print(a)


    

    




[[ 0  1  2  3]
 [ 4  5  6  7]
 [ 8  9 10 11]]

In [7]:

    

print(np.tril(a))


    

    




[[ 0  0  0  0]
 [ 4  5  0  0]
 [ 8  9 10  0]]

In [8]:

    

print(np.tril(a, k=-1))


    

    




[[0 0 0 0]
 [4 0 0 0]
 [8 9 0 0]]

In [9]:

    

print(np.tril(np.arange(32).reshape(2, 4, 4)))


    

    




[[[ 0  0  0  0]
  [ 4  5  0  0]
  [ 8  9 10  0]
  [12 13 14 15]]

 [[16  0  0  0]
  [20 21  0  0]
  [24 25 26  0]
  [28 29 30 31]]]

In [10]:

    

print(np.tril(np.arange(16).reshape(1, 1, 4, 4)))


    

    




[[[[ 0  0  0  0]
   [ 4  5  0  0]
   [ 8  9 10  0]
   [12 13 14 15]]]]

In [11]:

    

a_tril = np.tril(np.arange(16).reshape(4, 4))
print(a_tril)


    

    




[[ 0  0  0  0]
 [ 4  5  0  0]
 [ 8  9 10  0]
 [12 13 14 15]]

In [12]:

    

print(a_tril.T)


    

    




[[ 0  4  8 12]
 [ 0  5  9 13]
 [ 0  0 10 14]
 [ 0  0  0 15]]

In [13]:

    

print(a_tril.T.T)


    

    




[[ 0  0  0  0]
 [ 4  5  0  0]
 [ 8  9 10  0]
 [12 13 14 15]]