dictances 1.5.0

Distances and divergences between distributions implemented in python.

Distances and divergences between dictionaries implemented in python 3.6.

In the complexity notations, n is len(a) and m is len(b).

The samples are dictionaries generated by the test utilities here.

How do I get it?

Just type into your terminal:

pip install dictances

Basic example

For each metric, an example is present in the folder examples. Here’s a basic example for those too lazy to click links (like me).

import random
from dictances import cosine, euclidean, canberra
random.seed(42)  # for reproducibility

# Simple function to generate the example dictionaries


def generate_example_dict(n=1000):
    return {random.randint(0, 1000): random.uniform(0, 1000) for i in range(n)}


a, b = generate_example_dict(), generate_example_dict()

print(cosine(a, b))
# >>> 0.52336690346601

print(euclidean(a, b))
# >>> 15119.400349404095

print(canberra(a, b))
# >>> 624.9088876554047

Metrics table

Metric name	Usage example	Average time on sample	Complexity
Euclidean distance	euclidean	90.4 µs ± 2.5 µs
Squared variation	squared_variation	90.8 µs ± 1.43
Total variation	total_variation	92.3 µs ± 1.28 µs
Nth variation	nth_variation	91.1 µs ± 1.2 µs
Manhattan distance	manhattan	92.7 µs ± 1.43 µs
Mean absolute error	mae	92.3 µs ± 1.28 µs
Mean squared error	mse	91.1 µs ± 1.2 µs
Chebyshev distance	chebyshev	101 µs ± 2.14 µs
Minkowski distance	minkowsky	91.1 µs ± 2.05 µs
Canberra distance	canberra	71.8 µs ± 1.95 µs
Cosine distance	cosine	61.3 µs ± 835 ns
Pearson distance	pearson	46.9 µs ± 1.23 µs
Hamming distance	hamming	28.7 µs ± 784 ns
Normalized Total Variation	normal_total_variation	34.6 µs ± 543 ns
Kullback Leibler divergence	kullback_leibler	24 µs ± 587 ns
Jensen Shannon divergence	jensen_shannon	38.2 µs ± 1.18 µs
Bhattacharyya distance	bhattacharyya	32.7 µs ± 655 ns
Hellinger distance	hellinger	42 µs ± 467 ns

Test computer specifications

The computer on which the metrics where timed had the following specifications:

Computer specifications
Model Name	MacBook Pro
Processor Name	Intel Core i7
Processor Speed	2.3 GHz
Number of Processors	1
Total Number of Cores	4
L2 Cache (per Core)	256 KB
L3 Cache	6 MB
Memory	16 GB