Get the Kronecker Product of Two Arrays with Different Dimensions in Python

To get the Kronecker product of two arrays with different dimensionas, use the numpy.kron() method in Python Numpy. Compute the Kronecker product, a composite array made of blocks of the second array scaled by the first

The function assumes that the number of dimensions of a and b are the same, if necessary, prepending the smallest with ones. If a.shape = (r0,r1,..,rN) and b.shape = (s0,s1,...,sN), the Kronecker product has shape (r0*s0, r1*s1, ..., rN*SN). The elements are products of elements from a and b, organized explicitly by −

# kron(a,b)[k0,k1,...,kN] = a[i0,i1,...,iN] * b[j0,j1,...,jN]

Steps

At first, import the required libraries −

import numpy as np

Creating two numpy arrays with different dimensions using the arange() and reshape() method −

arr1 = np.arange(20).reshape((2,5,2))
arr2 = np.arange(6).reshape((2,3))

Display the arrays −

print("Array1...\n",arr1)
print("\nArray2...\n",arr2)

Check the Dimensions of both the arrays −

print("\nDimensions of Array1...\n",arr1.ndim)
print("\nDimensions of Array2...\n",arr2.ndim)

Check the Shape of both the arrays −

print("\nShape of Array1...\n",arr1.shape)
print("\nShape of Array2...\n",arr2.shape)

To get the Kronecker product of two arrays, use the numpy.kron() method in Python −

print("\nResult (Kronecker product)...\n",np.kron(arr1, arr2))

Example

import numpy as np

# Creating two numpy arrays with different dimensions using the arange() and reshape() method
arr1 = np.arange(20).reshape((2,5,2))
arr2 = np.arange(6).reshape((2,3))

# Display the arrays
print("Array1...\n",arr1)
print("\nArray2...\n",arr2)

# Check the Dimensions of both the array
print("\nDimensions of Array1...\n",arr1.ndim)
print("\nDimensions of Array2...\n",arr2.ndim)

# Check the Shape of both the array
print("\nShape of Array1...\n",arr1.shape)
print("\nShape of Array2...\n",arr2.shape)

# To get the Kronecker product of two arrays, use the numpy.kron() method in Python Numpy
print("\nResult (Kronecker product)...\n",np.kron(arr1, arr2))

Output

Array1...
[[[ 0 1]
[ 2 3]
[ 4 5]
[ 6 7]
[ 8 9]]

[[10 11]
[12 13]
[14 15]
[16 17]
[18 19]]]

Array2...
[[0 1 2]
[3 4 5]]

Dimensions of Array1...
3

Dimensions of Array2...
2

Shape of Array1...
(2, 5, 2)

Shape of Array2...
(2, 3)

Result (Kronecker product)...
[[[ 0 0 0 0 1 2]
[ 0 0 0 3 4 5]
[ 0 2 4 0 3 6]
[ 6 8 10 9 12 15]
[ 0 4 8 0 5 10]
[12 16 20 15 20 25]
[ 0 6 12 0 7 14]
[18 24 30 21 28 35]
[ 0 8 16 0 9 18]
[24 32 40 27 36 45]]

[[ 0 10 20 0 11 22]
[30 40 50 33 44 55]
[ 0 12 24 0 13 26]
[36 48 60 39 52 65]
[ 0 14 28 0 15 30]
[42 56 70 45 60 75]
[ 0 16 32 0 17 34]
[48 64 80 51 68 85]
[ 0 18 36 0 19 38]
[54 72 90 57 76 95]]]