Algorithms and Hardness for Estimating Statistical Similarity

Fuente: arXiv
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Main Authors: Bhattacharyya, Arnab, Gayen, Sutanu, Meel, Kuldeep S., Myrisiotis, Dimitrios, Pavan, A., Vinodchandran, N. V.
Format: Preprint
Published: 2025
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author Bhattacharyya, Arnab
Gayen, Sutanu
Meel, Kuldeep S.
Myrisiotis, Dimitrios
Pavan, A.
Vinodchandran, N. V.
author_facet Bhattacharyya, Arnab
Gayen, Sutanu
Meel, Kuldeep S.
Myrisiotis, Dimitrios
Pavan, A.
Vinodchandran, N. V.
contents We introduce and study the computational problem of determining statistical similarity between probability distributions. For distributions $P$ and $Q$ over a finite sample space, their statistical similarity is defined as $S_{\mathrm{stat}}(P, Q) := \sum_x \min(P(x), Q(x))$. Despite its fundamental nature as a measure of similarity between distributions, capturing essential concepts such as Bayes error in prediction and hypothesis testing, this computational problem has not been previously explored. Recent work on computing statistical distance has established that, somewhat surprisingly, even for the simple class of product distributions, exactly computing statistical similarity is $\#\mathsf{P}$-hard. This motivates the question of designing approximation algorithms for statistical similarity. Our first contribution is a Fully Polynomial-Time deterministic Approximation Scheme (FPTAS) for estimating statistical similarity between two product distributions. Furthermore, we also establish a complementary hardness result. In particular, we show that it is $\mathsf{NP}$-hard to estimate statistical similarity when $P$ and $Q$ are Bayes net distributions of in-degree $2$.
format Preprint
id arxiv_https___arxiv_org_abs_2502_10527
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Algorithms and Hardness for Estimating Statistical Similarity
Bhattacharyya, Arnab
Gayen, Sutanu
Meel, Kuldeep S.
Myrisiotis, Dimitrios
Pavan, A.
Vinodchandran, N. V.
Data Structures and Algorithms
Computational Complexity
We introduce and study the computational problem of determining statistical similarity between probability distributions. For distributions $P$ and $Q$ over a finite sample space, their statistical similarity is defined as $S_{\mathrm{stat}}(P, Q) := \sum_x \min(P(x), Q(x))$. Despite its fundamental nature as a measure of similarity between distributions, capturing essential concepts such as Bayes error in prediction and hypothesis testing, this computational problem has not been previously explored. Recent work on computing statistical distance has established that, somewhat surprisingly, even for the simple class of product distributions, exactly computing statistical similarity is $\#\mathsf{P}$-hard. This motivates the question of designing approximation algorithms for statistical similarity. Our first contribution is a Fully Polynomial-Time deterministic Approximation Scheme (FPTAS) for estimating statistical similarity between two product distributions. Furthermore, we also establish a complementary hardness result. In particular, we show that it is $\mathsf{NP}$-hard to estimate statistical similarity when $P$ and $Q$ are Bayes net distributions of in-degree $2$.
title Algorithms and Hardness for Estimating Statistical Similarity
topic Data Structures and Algorithms
Computational Complexity
url https://arxiv.org/abs/2502.10527