How to count occurances of multiple items in numpy?

Question

Assume the folowing numpy array:

[1,2,3,1,2,3,1,2,3,1,2,2]

I want to count([1,2]) to count all occurrences of 1 and 2, in a single run, yielding something like

[4, 5]

corresponding to a [1, 2] input.

Is it supported in numpy?

https://stackoverflow.com/a/28663910/4940954 Could you do something like this? This will give you the counts of each number. — brandonbanks, Nov 27 '19 at 20:55

score 1 · Accepted Answer · edited Sep 08 '22 at 07:58

1

# Setting your input to an array
array = np.array([1,2,3,1,2,3,1,2,3,1,2,2])

# Find the unique elements and get their counts
unique, counts = np.unique(array, return_counts=True)

# Setting the numbers to get counts for as a set
search = {1, 2}

# Gets the counts for the elements in search
search_counts = [counts[i] for i, x in enumerate(unique) if x in search]

This will output [4, 5]

edited Sep 08 '22 at 07:58

Gulzar

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answered Nov 27 '19 at 21:03

Spencer Stream

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How to count occurances of multiple items in numpy?

1 Answers1