NumPy Product

[Bhaktey10]

In this tutorial you will learn:

• What is the product of numbers?
  
• Implementation of product using different functions in Python
  
• Python Syntax
  

Product of Number

Product is just another name for the operation of multiplication. It is a very common operation in the world of computation, mathematics and science. Product is taken of more than one elements which are contained in data structures like list, tuple, array etc
Implementation of Product

Function prod() is used to get the product of all the elements of the array, the function takes in an array as an only mandatory parameter and returns a number as output. The result of this example will be 1644 (4 x 8 x 12 x 16)

1. #importing the NumPy library
   
2. import
   
   numpy as
   
   np
   
3. #declaring an array
   
4. my_arr=
   
   np.array
   
   (
   
   [
   
   4
   
   ,
   
   8
   
   ,
   
   12
   
   ,
   
   16
   
   ]
   
   )
   
5. print
   
   (
   
   'Array of which product is being taken:'
   
   ,
   
   my_arr)
   
6. #finding the product of contents of an array
   
7. res =
   
   np.prod
   
   (
   
   my_arr)
   
8. #printing the result
   
9. print
   
   (
   
   'The result of prod() function:'
   
   ,
   
   res)
   

The prod() function can return the result of each array separately if we define its parameter “axis” equal to one. Here we will be taking three arrays and will find the prod of three arrays separately.

1. #importing the NumPy library
   
2. import
   
   numpy as
   
   np
   
3. #declaring three arrays
   
4. my_arr1=
   
   np.array
   
   (
   
   [
   
   1
   
   ,
   
   3
   
   ,
   
   5
   
   ,
   
   7
   
   ]
   
   )
   
5. my_arr2=
   
   np.array
   
   (
   
   [
   
   2
   
   ,
   
   4
   
   ,
   
   6
   
   ,
   
   8
   
   ]
   
   )
   
6. my_arr3=
   
   np.array
   
   (
   
   [
   
   3
   
   ,
   
   6
   
   ,
   
   9
   
   ,
   
   12
   
   ]
   
   )
   
7. print
   
   (
   
   'Three Arrays of which product is being taken:'
   
   ,
   
   my_arr1,
   
   my_arr2,
   
   my_arr3)
   
8. #finding the product of contents of 3 arrays separately
   
9. res =
   
   np.prod
   
   (
   
   [
   
   my_arr1,
   
   my_arr2,
   
   my_arr3]
   
   ,
   
   axis=
   
   1
   
   )
   
10. #printing the result
    
11. print
    
    (
    
    'The result of prod() function with axis = 1:'
    
    ,
    
    res)
    

NumPy provides another function ‘cumprod()’, the function takes in an array and at each index gives out a cumulative product after multiplying up all the elements of the lower indexes of the array.

1. #importing the NumPy library
   
2. import
   
   numpy as
   
   np
   
3. #declaring an array
   
4. arr=
   
   np.array
   
   (
   
   [
   
   10
   
   ,
   
   20
   
   ,
   
   30
   
   ,
   
   40
   
   ]
   
   )
   
5. print
   
   (
   
   'Array of which cummulative product is being taken:'
   
   ,
   
   arr)
   
6. #taking the cummulative product of the contents of an array
   
7. res =
   
   np.cumprod
   
   (
   
   arr)
   
8. #printing the result
   
9. print
   
   (
   
   'The result of cumprod() function:'
   
   ,
   
   res)
   

Book traversal links for NumPy Product

• ‹ NumPy Permutations
  
• Up
  
• NumPy Random ›
  

Download