numpy.bincount() in Python

Last Updated : 17 Nov, 2020

In an array of +ve integers, the numpy.bincount() method counts the occurrence of each element. Each bin value is the occurrence of its index. One can also set the bin size accordingly. Syntax :

numpy.bincount(arr, weights = None, min_len = 0)

Parameters :

arr     : [array_like, 1D]Input array, having positive numbers
weights : [array_like, optional]same shape as that of arr
min_len : Minimum number of bins we want in the output array

Return :

Output array with no. of occurrence of index value of bin in input - arr. 
Output array, by default is of the length max element of arr + 1. 
Here size of the output array would be max(input_arr)+1.

Code 1 : Working of bincount() in NumPy

Python3

# Python Program explaining 
# working of numpy.bincount() method

import numpy as geek

# 1D array with +ve integers
array1 = [1, 6, 1, 1, 1, 2, 2]
bin = geek.bincount(array1)
print("Bincount output  : \n ", bin)
print("size of bin : ", len(bin), "\n")

array2 = [1, 5, 5, 5, 4, 5, 5, 2, 2, 2]
bin = geek.bincount(array2)
print("Bincount output  : \n ", bin)
print("size of bin : ", len(bin), "\n")

# using min_length attribute
length = 10
bin1 = geek.bincount(array2, None, length)
print("Bincount output  : \n ", bin1)

print("size of bin : ", len(bin1), "\n")

Output :

Bincount output  : 
  [0 4 2 0 0 0 1]
size of bin :  7 

Bincount output  : 
  [0 1 3 0 1 5]
size of bin :  6 

Bincount output  : 
  [0 1 3 0 1 5 0 0 0 0]
size of bin :  10

Code 2 : We can perform addition as per element with bincount() weight

Python3

# Python Program explaining 
# working of numpy.bincount() method

import numpy as geek

# 1D array with +ve integers
array2 = [10, 11, 4, 6, 2, 1, 9]
array1 = [1, 3, 1, 3, 1, 2, 2]

# array2 : weight
bin = geek.bincount(array1, array2)
print("Summation element-wise : \n", bin)

#index 0 : 0
#index 1 : 10 + 4 + 2 = 16
#index 2 : 1 + 9 = 10
#index 3 : 11 + 6 = 17

Output :

Summation element-wise : 
 [  0.  16.  10.  17.]

References : https://numpy.org/doc/stable/reference/generated/numpy.bincount.html#numpy.bincount .

Python Introduction

Mohit Gupta

Improve

Article Tags :

Practice Tags :

python

numpy.bincount() in Python

Similar Reads

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

numpy.bincount() in Python

Similar Reads

Python Fundamentals

Python Data Structures

Advanced Python

Data Science with Python

Web Development with Python

Python Practice

Thank You!

What kind of Experience do you want to share?

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.