/Python/Numpy count occurrences in array

Numpy count occurrences in array

How to count occurences of a certain item in a numpy array

>>> import numpy as np
>>> y = np.array([1, 2, 2, 2, 2, 0, 2, 3, 3, 3, 0, 0, 2, 2, 0])

>>> np.count_nonzero(y == 1)
1
>>> np.count_nonzero(y == 2)
7
>>> np.count_nonzero(y == 3)
3

Source: stackoverflow.com

Count values in array python

a = numpy.array([0, 3, 0, 1, 0, 1, 2, 1, 0, 0, 0, 0, 1, 3, 4])
unique, counts = numpy.unique(a, return_counts=True)
dict(zip(unique, counts))

# {0: 7, 1: 4, 2: 1, 3: 2, 4: 1}

Source: stackoverflow.com

Numpy count occurrences in array

unique, counts = numpy.unique(a, return_counts=True)

Numpy count occurrences in interval array

# credit to Stack Overflow user in source link
# a is a numpy array
# Note: the following syntax allows you to count the number of elements x
# of the array such that 25 < x < 100 
((a > 25) & (a < 100)).sum()

Source: stackoverflow.com

Similar codes

15 votes251 views3 answers
Python get lan ip
Python
11 votes262 views6 answers
Python file size
Python
0 vote223 views1 answer
Python get city name from IP
Python
5 votes338 views2 answers
Append element an array in python
Python
10 votes244 views6 answers
Variable in python
Python
0 vote318 views1 answer
RuntimeError: Expected object of type torch.FloatTensor but found type torch.cuda.FloatTensor for argument
Python
8 votes250 views1 answer
Charmap codec can't encode character
Python
0 vote258 views1 answer
Anagram Game
Python
0 vote256 views1 answer
Sikuli guide text
Python
0 vote234 views1 answer
Http.client.invalidurl: url can't
Python