In NumPy, we can find Einstein’s summation convention of two given multidimensional arrays with the help of numpy.einsum(). We will pass two arrays as a parameter and it will return the Einstein’s summation convention.
Syntax: numpy.einsum()
Parameter: Two arrays.
Return : It will return the Einstein’s summation convention.
Example 1:
import numpy as np
array1 = np.array([1, 2, 3])
array2 = np.array([4, 5, 6])
# Original 1-d arrays
print(array1)
print(array2)
r = np.einsum("n,n", a, b)
# Einstein’s summation convention of
# the said arrays
print(r)
Output:
[1 2 3] [4 5 6] 32
Example 2:
import numpy as np
ar1 = np.arange(9).reshape(3, 3)
ar2 = np.arange(10, 19).reshape(3, 3)
# Original Higher dimension
print(ar1)
print(ar2)
print("")
r = np.einsum("mk,kn", ar1, ar2)
# Einstein’s summation convention of
# the said arrays
print(r)
Output:
[[0 1 2] [3 4 5] [6 7 8]] [[10 11 12] [13 14 15] [16 17 18]] [[ 45 48 51] [162 174 186] [279 300 321]]