NumPy Products
Products
To find the product of the elements in an array, use theprod() function.
Example
Find the product of the elements of this array:
import numpy as np
arr = np.array([1, 2, 3, 4])
x = np.prod(arr)
print(x)
Try it Yourself »arr = np.array([1, 2, 3, 4])
x = np.prod(arr)
print(x)
Returns:24 because 1*2*3*4 = 24
Example
Find the product of the elements of two arrays:
import numpy as np
arr1 = np.array([1, 2, 3, 4])
arr2 = np.array([5, 6, 7, 8])
x = np.prod([arr1, arr2])
print(x)
Try it Yourself »arr1 = np.array([1, 2, 3, 4])
arr2 = np.array([5, 6, 7, 8])
x = np.prod([arr1, arr2])
print(x)
Returns:40320 because 1*2*3*4*5*6*7*8 = 40320
Product Over an Axis
If you specifyaxis=1, NumPy will return the product of each array.
Example
Perform summation in the following array over 1st axis:
import numpy as np
arr1 = np.array([1, 2, 3, 4])
arr2 = np.array([5, 6, 7, 8])
newarr = np.prod([arr1, arr2], axis=1)
print(newarr)
Try it Yourself »arr1 = np.array([1, 2, 3, 4])
arr2 = np.array([5, 6, 7, 8])
newarr = np.prod([arr1, arr2], axis=1)
print(newarr)
Returns:[24 1680]
Cummulative Product
Cummulative product means taking the product partially.
E.g. The partial product of [1, 2, 3, 4] is [1, 1*2, 1*2*3, 1*2*3*4] = [1, 2, 6, 24]
Perfom partial sum with thecumprod() function.
Example
Take cummulative product of all elements for following array:
import numpy as np
arr = np.array([5, 6, 7, 8])
newarr = np.cumprod(arr)
print(newarr)
Try it Yourself »arr = np.array([5, 6, 7, 8])
newarr = np.cumprod(arr)
print(newarr)
Returns:[5 30 210 1680]
