dictances 1.1.4

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	53.7 µs ± 981 ns
Squared variation	squared_variation	50.6 µs ± 982 ns
Total variation	total_variation	50.6 µs ± 2.75 µs
Nth variation	nth_variation	50.6 µs ± 1.07 µs
Manhattan distance	manhattan	51 µs ± 1.2 µs
Mean absolute error	mae	51.9 µs ± 2.4 µs
Mean squared error	mse	51.8 µs ± 1.67 µs
Chebyshev distance	chebyshev	49.8 µs ± 628 ns
Minkowski distance	minkowsky	50.4 µs ± 2.94 µs
Canberra distance	canberra	30.9 µs ± 340 ns
Cosine distance	cosine	41.7 µs ± 1.42 µs
Pearson distance	pearson	49.8 µs ± 2.51 µs
Hamming distance	hamming	5.57 µs ± 191 ns
Kullback Leibler divergence	kullback_leibler	31.6 µs ± 591 ns
Jensen Shannon divergence	jensen_shannon	21.1 µs ± 442 ns
Bhattacharyya distance	bhattacharyya	13.7 µs ± 71.9 ns
Hellinger distance	hellinger	16.8 µs ± 372 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