# Compute the tensor dot product in Python

PythonNumpyServer Side ProgrammingProgramming

Given two tensors, a and b, and an array_like object containing two array_like objects, (a_axes, b_axes), sum the products of a’s and b’s elements (components) over the axes specified by a_axes and b_axes. The third argument can be a single non-negative integer_like scalar, N; if it is such, then the last N dimensions of a and the first N dimensions of b are summed over.

To compute the tensor dot product, use the numpy.tensordot() method in Python. The a, b parameters are Tensors to “dot”. The axes parameter, integer_like If an int N, sum over the last N axes of a and the first N axes of b in order. The sizes of the corresponding axes must match.

## Steps

At first, import the required libraries −

import numpy as np

Creating two numpy 3D arrays using the array() method −

arr1 = np.arange(60.).reshape(3,4,5)
arr2 = np.arange(24.).reshape(4,3,2)

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 compute the tensor dot product, use the numpy.tensordot() method in Python. The a, b parameters are Tensors to “dot” −

print("\nTensor dot product...\n", np.tensordot(arr1,arr2, axes=([1,0],[0,1])))


## Example

import numpy as np

# Creating two numpy 3D arrays using the array() method
arr1 = np.arange(60.).reshape(3,4,5)
arr2 = np.arange(24.).reshape(4,3,2)

# 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 compute the tensor dot product, use the numpy.tensordot() method in Python
# The a, b parameters are Tensors to “dot”.
print("\nTensor dot product...\n", np.tensordot(arr1,arr2, axes=([1,0],[0,1])))

## Output

Array1...
[[[ 0. 1. 2. 3. 4.]
[ 5. 6. 7. 8. 9.]
[10. 11. 12. 13. 14.]
[15. 16. 17. 18. 19.]]

[[20. 21. 22. 23. 24.]
[25. 26. 27. 28. 29.]
[30. 31. 32. 33. 34.]
[35. 36. 37. 38. 39.]]

[[40. 41. 42. 43. 44.]
[45. 46. 47. 48. 49.]
[50. 51. 52. 53. 54.]
[55. 56. 57. 58. 59.]]]

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

[[ 6. 7.]
[ 8. 9.]
[10. 11.]]

[[12. 13.]
[14. 15.]
[16. 17.]]

[[18. 19.]
[20. 21.]
[22. 23.]]]

Dimensions of Array1...
3

Dimensions of Array2...
3

Shape of Array1...
(3, 4, 5)

Shape of Array2...
(4, 3, 2)

Tensor dot product...
[[4400. 4730.]
[4532. 4874.]
[4664. 5018.]
[4796. 5162.]
[4928. 5306.]]