In [1]:

    

import numpy as np


    

In [2]:

    

l_2d = [[0, 1, 2], [3, 4, 5]]
print(l_2d)


    

    




[[0, 1, 2], [3, 4, 5]]

In [3]:

    

print(type(l_2d))


    

    




<class 'list'>

In [4]:

    

arr = np.array([[0, 1, 2], [3, 4, 5]])
print(arr)


    

    




[[0 1 2]
 [3 4 5]]

In [5]:

    

print(type(arr))


    

    




<class 'numpy.ndarray'>

In [6]:

    

arr = np.arange(6)
print(arr)


    

    




[0 1 2 3 4 5]

In [7]:

    

arr = np.arange(6).reshape((2, 3))
print(arr)


    

    




[[0 1 2]
 [3 4 5]]

In [8]:

    

mat = np.matrix([[0, 1, 2], [3, 4, 5]])
print(mat)


    

    




[[0 1 2]
 [3 4 5]]

In [9]:

    

print(type(mat))


    

    




<class 'numpy.matrix'>

In [10]:

    

mat = np.matrix(arr)
print(mat)


    

    




[[0 1 2]
 [3 4 5]]

In [11]:

    

print(type(mat))


    

    




<class 'numpy.matrix'>

In [12]:

    

mat_1d = np.matrix([0, 1, 2])
print(mat_1d)


    

    




[[0 1 2]]

In [13]:

    

print(type(mat_1d))


    

    




<class 'numpy.matrix'>

In [14]:

    

print(mat_1d.shape)


    

    




(1, 3)

In [15]:

    

# mat_3d = np.matrix([[[0, 1, 2]]])
# ValueError: matrix must be 2-dimensional


    

In [16]:

    

print(l_2d)


    

    




[[0, 1, 2], [3, 4, 5]]

In [17]:

    

print(l_2d[0][1])


    

    




1

In [18]:

    

l_2d[0][1] = 100
print(l_2d)


    

    




[[0, 100, 2], [3, 4, 5]]

In [19]:

    

print(arr)


    

    




[[0 1 2]
 [3 4 5]]

In [20]:

    

print(arr[0, 1])


    

    




1

In [21]:

    

arr[0, 1] = 100
print(arr)


    

    




[[  0 100   2]
 [  3   4   5]]

In [22]:

    

l_2d = [[0, 1, 2], [3, 4, 5]]
print(l_2d)


    

    




[[0, 1, 2], [3, 4, 5]]

In [23]:

    

print([list(x) for x in list(zip(*l_2d))])


    

    




[[0, 3], [1, 4], [2, 5]]

In [24]:

    

arr = np.arange(6).reshape((2, 3))
print(arr)


    

    




[[0 1 2]
 [3 4 5]]

In [25]:

    

print(arr.T)


    

    




[[0 3]
 [1 4]
 [2 5]]

In [26]:

    

l_2d_1 = [[0, 1, 2], [3, 4, 5]]
l_2d_2 = [[0, 2, 4], [6, 8, 10]]


    

In [27]:

    

print(l_2d_1 + l_2d_2)


    

    




[[0, 1, 2], [3, 4, 5], [0, 2, 4], [6, 8, 10]]

In [28]:

    

# print(l_2d_1 - l_2d_2)
# TypeError: unsupported operand type(s) for -: 'list' and 'list'


    

In [29]:

    

arr1 = np.arange(6).reshape((2, 3))
print(arr1)


    

    




[[0 1 2]
 [3 4 5]]

In [30]:

    

arr2 = np.arange(0, 12, 2).reshape((2, 3))
print(arr2)


    

    




[[ 0  2  4]
 [ 6  8 10]]

In [31]:

    

print(arr1 + arr2)


    

    




[[ 0  3  6]
 [ 9 12 15]]

In [32]:

    

print(arr1 - arr2)


    

    




[[ 0 -1 -2]
 [-3 -4 -5]]

In [33]:

    

mat1 = np.matrix(arr1)
mat2 = np.matrix(arr2)


    

In [34]:

    

print(mat1 + mat2)


    

    




[[ 0  3  6]
 [ 9 12 15]]

In [35]:

    

print(mat1 - mat2)


    

    




[[ 0 -1 -2]
 [-3 -4 -5]]

In [36]:

    

print(l_2d_1 * 2)


    

    




[[0, 1, 2], [3, 4, 5], [0, 1, 2], [3, 4, 5]]

In [37]:

    

# print(l_2d_1 * l_2d_2)
# TypeError: can't multiply sequence by non-int of type 'list'


    

In [38]:

    

print(arr1 * 2)


    

    




[[ 0  2  4]
 [ 6  8 10]]

In [39]:

    

print(mat1 * 2)


    

    




[[ 0  2  4]
 [ 6  8 10]]

In [40]:

    

print(np.multiply(arr1, arr2))


    

    




[[ 0  2  8]
 [18 32 50]]

In [41]:

    

print(np.multiply(mat1, mat2))


    

    




[[ 0  2  8]
 [18 32 50]]

In [42]:

    

print(arr1 * arr2)


    

    




[[ 0  2  8]
 [18 32 50]]

In [43]:

    

arr1 = np.arange(4).reshape((2, 2))
print(arr1)


    

    




[[0 1]
 [2 3]]

In [44]:

    

arr2 = np.arange(6).reshape((2, 3))
print(arr2)


    

    




[[0 1 2]
 [3 4 5]]

In [45]:

    

print(np.dot(arr1, arr2))


    

    




[[ 3  4  5]
 [ 9 14 19]]

In [46]:

    

print(arr1.dot(arr2))


    

    




[[ 3  4  5]
 [ 9 14 19]]

In [47]:

    

print(np.matmul(arr1, arr2))


    

    




[[ 3  4  5]
 [ 9 14 19]]

In [48]:

    

print(arr1 @ arr2)


    

    




[[ 3  4  5]
 [ 9 14 19]]

In [49]:

    

mat1 = np.matrix(arr1)
mat2 = np.matrix(arr2)


    

In [50]:

    

print(np.dot(mat1, mat2))


    

    




[[ 3  4  5]
 [ 9 14 19]]

In [51]:

    

print(mat1.dot(mat2))


    

    




[[ 3  4  5]
 [ 9 14 19]]

In [52]:

    

print(np.matmul(mat1, mat2))


    

    




[[ 3  4  5]
 [ 9 14 19]]

In [53]:

    

print(mat1 @ mat2)


    

    




[[ 3  4  5]
 [ 9 14 19]]

In [54]:

    

print(mat1 * mat2)


    

    




[[ 3  4  5]
 [ 9 14 19]]

In [55]:

    

arr = np.arange(1, 5).reshape(2, 2)
print(arr)


    

    




[[1 2]
 [3 4]]

In [56]:

    

print(arr**2)


    

    




[[ 1  4]
 [ 9 16]]

In [57]:

    

mat = np.matrix(arr)
print(mat)


    

    




[[1 2]
 [3 4]]

In [58]:

    

print(mat**2)


    

    




[[ 7 10]
 [15 22]]

In [59]:

    

print(mat**2 == mat * mat)


    

    




[[ True  True]
 [ True  True]]

In [60]:

    

print(mat**3 == mat * mat * mat)


    

    




[[ True  True]
 [ True  True]]

In [61]:

    

# print(arr**-1)
# ValueError: Integers to negative integer powers are not allowed.


    

In [62]:

    

arr_f = np.array(arr, dtype=float)
print(arr_f**-1)


    

    




[[1.         0.5       ]
 [0.33333333 0.25      ]]

In [63]:

    

print(mat**-1)


    

    




[[-2.   1. ]
 [ 1.5 -0.5]]

In [64]:

    

print(mat**-2)


    

    




[[ 5.5  -2.5 ]
 [-3.75  1.75]]

In [65]:

    

print(mat**-2 == mat**-1 * mat**-1)


    

    




[[ True  True]
 [ True  True]]

In [66]:

    

print(mat**-3 == mat**-1 * mat**-1 * mat**-1)


    

    




[[ True  True]
 [ True  True]]