NumPy

• NumPy contains many, many routines for creating and manipulating vectors and arrays.

>>> import numpy as np
>>> a = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
>>> x = np.array([1, 1, 1])
>>> y = np.arange(10, 13)
>>> y
array([10, 11, 12])
>>> x + y
array([11, 12, 13])
>>> np.dot(a, x)
array([ 6, 15, 24])
>>> a.transpose()
array([[1, 4, 7],
       [2, 5, 8],
       [3, 6, 9]])
>>> a[2,2]
9
>>> a[:2,:2]
array([[1, 2],
       [4, 5]])