matmul

Description

Calculate the matrix product of two arrays.

Mandatory Input Parameters

Parameter	Type	Description
x1	array_like	The first argument.
x2	array_like	The second argument.

Note that scalars are not allowed. Otherwise, an exception is raised.

Optional Input Parameters

Parameter	Type	Default Value	Description
out	ndarray	None	Location into which the result is stored. If provided, it must have a shape that matches the signature (n,k),(k,m)->(n,m). If not provided or None, a freshly-allocated array is returned.
**kwargs	-	-	For other keyword arguments, see the NumPy ufunc docs.

Return Value

Type	Description
ndarray	Matrix product of the inputs. This is a scalar only when both x1 and x2 are 1-D vectors.

Examples

>>> import numpy as np
>>> a = np.array([1,2,3])
>>> b = np.array([0,1,2])
>>> np.inner(a, b)
8
>>> 
>>> a = np.arange(24).reshape((2,3,4))
>>> a
array([[[ 0,  1,  2,  3],
        [ 4,  5,  6,  7],
        [ 8,  9, 10, 11]],

       [[12, 13, 14, 15],
        [16, 17, 18, 19],
        [20, 21, 22, 23]]])
>>> b = np.arange(4)
>>> b
array([0, 1, 2, 3])
>>> np.inner(a, b)
array([[ 14,  38,  62],
       [ 86, 110, 134]])
>>> 
>>> a = np.arange(2).reshape((1,1,2))
>>> b = np.arange(6).reshape((3,2))
>>> np.inner(a, b)
array([[[1, 3, 5]]])
>>> 
>>> a = np.eye(2)
>>> a
array([[1., 0.],
       [0., 1.]])
>>> np.inner(a, 5)
array([[5., 0.],
       [0., 5.]])
>>>

Parent topic: Basic Statistics Functions