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Related papers: List-Decodable Mean Estimation in Nearly-PCA Time

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We introduce an expander-sketching framework for list-decodable linear regression that achieves sample complexity $\tilde{O}((d+\log(1/\delta))/\alpha)$, list size $O(1/\alpha)$, and near input-sparsity running time…

Machine Learning · Computer Science 2025-12-01 Herbod Pourali , Sajjad Hashemian , Ebrahim Ardeshir-Larijani

We study the problem of robustly estimating the mean or location parameter without moment assumptions. We show that for a large class of symmetric distributions, the same error as in the Gaussian setting can be achieved efficiently. The…

Data Structures and Algorithms · Computer Science 2023-11-09 Gleb Novikov , David Steurer , Stefan Tiegel

We make progress on two important problems regarding attribute efficient learnability. First, we give an algorithm for learning decision lists of length $k$ over $n$ variables using $2^{\tilde{O}(k^{1/3})} \log n$ examples and time…

Machine Learning · Computer Science 2007-05-23 Adam R. Klivans , Rocco A. Servedio

We study principal component analysis (PCA), where given a dataset in $\mathbb{R}^d$ from a distribution, the task is to find a unit vector $v$ that approximately maximizes the variance of the distribution after being projected along $v$.…

Machine Learning · Computer Science 2023-05-05 Ilias Diakonikolas , Daniel M. Kane , Ankit Pensia , Thanasis Pittas

The vast majority of theoretical results in machine learning and statistics assume that the available training data is a reasonably reliable reflection of the phenomena to be learned or estimated. Similarly, the majority of machine learning…

Machine Learning · Computer Science 2017-06-13 Moses Charikar , Jacob Steinhardt , Gregory Valiant

Let $p$ be an unknown and arbitrary probability distribution over $[0,1)$. We consider the problem of {\em density estimation}, in which a learning algorithm is given i.i.d. draws from $p$ and must (with high probability) output a…

Machine Learning · Computer Science 2014-11-04 Siu-On Chan , Ilias Diakonikolas , Rocco A. Servedio , Xiaorui Sun

We study the problem of list-decodable Gaussian covariance estimation. Given a multiset $T$ of $n$ points in $\mathbb R^d$ such that an unknown $\alpha<1/2$ fraction of points in $T$ are i.i.d. samples from an unknown Gaussian…

Data Structures and Algorithms · Computer Science 2023-05-02 Ilias Diakonikolas , Daniel M. Kane , Jasper C. H. Lee , Ankit Pensia , Thanasis Pittas

We study the problem of high-dimensional linear regression in a robust model where an $\epsilon$-fraction of the samples can be adversarially corrupted. We focus on the fundamental setting where the covariates of the uncorrupted samples are…

Machine Learning · Computer Science 2018-06-04 Ilias Diakonikolas , Weihao Kong , Alistair Stewart

Clustering is a fundamental problem in unsupervised machine learning with many applications in data analysis. Popular clustering algorithms such as Lloyd's algorithm and $k$-means++ can take $\Omega(ndk)$ time when clustering $n$ points in…

Machine Learning · Computer Science 2023-10-26 Moses Charikar , Monika Henzinger , Lunjia Hu , Maxmilian Vötsch , Erik Waingarten

In this work, we give efficient algorithms for privately estimating a Gaussian distribution in both pure and approximate differential privacy (DP) models with optimal dependence on the dimension in the sample complexity. In the pure DP…

Data Structures and Algorithms · Computer Science 2023-06-02 Daniel Alabi , Pravesh K. Kothari , Pranay Tankala , Prayaag Venkat , Fred Zhang

Robust covariance estimation is the following, well-studied problem in high dimensional statistics: given $N$ samples from a $d$-dimensional Gaussian $\mathcal{N}(\boldsymbol{0}, \Sigma)$, but where an $\varepsilon$-fraction of the samples…

Data Structures and Algorithms · Computer Science 2020-06-25 Jerry Li , Guanghao Ye

We present a fast, differentially private algorithm for high-dimensional covariance-aware mean estimation with nearly optimal sample complexity. Only exponential-time estimators were previously known to achieve this guarantee. Given $n$…

Machine Learning · Computer Science 2025-11-26 Gavin Brown , Samuel B. Hopkins , Adam Smith

In this work, we revisit the problem of estimating the mean and covariance of an unknown $d$-dimensional Gaussian distribution in the presence of an $\varepsilon$-fraction of adversarial outliers. The pioneering work of [DKK+16] gave a…

Data Structures and Algorithms · Computer Science 2021-10-25 Pravesh K. Kothari , Peter Manohar , Brian Hu Zhang

In the list-decodable learning setup, an overwhelming majority (say a $1-\beta$-fraction) of the input data consists of outliers and the goal of an algorithm is to output a small list $\mathcal{L}$ of hypotheses such that one of them agrees…

Data Structures and Algorithms · Computer Science 2019-05-14 Prasad Raghavendra , Morris Yau

We construct an algorithm, running in time $\tilde{\mathcal O}(N d + uK d)$, which is robust to outliers and heavy-tailed data and which achieves the subgaussian rate from [Lugosi, Mendelson] \begin{equation}\label{eq:intro_subgaus_rate}…

Statistics Theory · Mathematics 2019-06-28 Jules Depersin , Guillaume Lecué

Motivated by the need for distributed learning and optimization algorithms with low communication cost, we study communication efficient algorithms for distributed mean estimation. Unlike previous works, we make no probabilistic assumptions…

Machine Learning · Computer Science 2017-09-26 Ananda Theertha Suresh , Felix X. Yu , Sanjiv Kumar , H. Brendan McMahan

Stochastic approximation is a foundation for many algorithms found in machine learning and optimization. It is in general slow to converge: the mean square error vanishes as $O(n^{-1})$. A deterministic counterpart known as quasi-stochastic…

Optimization and Control · Mathematics 2024-03-26 Caio Kalil Lauand , Sean Meyn

We study the algorithmic problem of estimating the mean of heavy-tailed random vector in $\mathbb{R}^d$, given $n$ i.i.d. samples. The goal is to design an efficient estimator that attains the optimal sub-gaussian error bound, only assuming…

Statistics Theory · Mathematics 2020-02-19 Zhixian Lei , Kyle Luh , Prayaag Venkat , Fred Zhang

We introduce general tools for designing efficient private estimation algorithms, in the high-dimensional settings, whose statistical guarantees almost match those of the best known non-private algorithms. To illustrate our techniques, we…

Data Structures and Algorithms · Computer Science 2023-11-17 Hongjie Chen , Vincent Cohen-Addad , Tommaso d'Orsi , Alessandro Epasto , Jacob Imola , David Steurer , Stefan Tiegel

We study efficient algorithms for linear regression and covariance estimation in the absence of Gaussian assumptions on the underlying distributions of samples, making assumptions instead about only finitely-many moments. We focus on how…