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High-dimensional feature vectors are likely to contain sets of measurements that are approximate replicates of one another. In complex applications, or automated data collection, these feature sets are not known a priori, and need to be…

Methodology · Statistics 2020-10-07 Xin Bing , Florentina Bunea , Marten Wegkamp

We define a copula process which describes the dependencies between arbitrarily many random variables independently of their marginal distributions. As an example, we develop a stochastic volatility model, Gaussian Copula Process Volatility…

Methodology · Statistics 2010-06-24 Andrew Gordon Wilson , Zoubin Ghahramani

Generative models have the ability to synthesize data points drawn from the data distribution, however, not all generated samples are high quality. In this paper, we propose using a combination of coresets selection methods and ``entropic…

Machine Learning · Computer Science 2023-02-02 Omead Pooladzandi , Pasha Khosravi , Erik Nijkamp , Baharan Mirzasoleiman

In this paper we review Bernstein and grid-type copulas for arbitrary dimensions and general grid resolutions in connection with discrete random vectors possessing uniform margins. We further suggest a pragmatic way to fit the dependence…

Methodology · Statistics 2020-10-30 Dietmar Pfeifer , Doreen Strassburger , Joerg Philipps

The purpose of this paper is twofold. First, we provide a novel characterization of independence of random vectors based on the checkerboard approximation to a multivariate copula. Using this result, we then propose a new family of tests of…

Statistics Theory · Mathematics 2019-06-07 José M. González-Barrios , Eduardo Gutiérrez-Peña , Juan D. Nieves , Raúl Rueda

We propose semiparametric estimators, called elliptical skew-(S)KEPTIC, for efficiently and robustly estimating non-Gaussian graphical models. Our approach extends the semiparametric elliptical framework to the meta skew-elliptical family,…

Methodology · Statistics 2025-12-03 Gabriele Di Luzio , Giacomo Morelli

We propose a relative entropy gradient sampler (REGS) for sampling from unnormalized distributions. REGS is a particle method that seeks a sequence of simple nonlinear transforms iteratively pushing the initial samples from a reference…

Machine Learning · Statistics 2021-10-07 Xingdong Feng , Yuan Gao , Jian Huang , Yuling Jiao , Xu Liu

When modeling the distribution of a multivariate continuous random vector using the so-called \emph{copula approach}, it is not uncommon to have ties in the coordinate samples of the available data because of rounding or lack of measurement…

Methodology · Statistics 2017-02-07 Ivan Kojadinovic

The formation of self-gravitating systems is studied by simulating the collapse of a set of N particles which are generated from several distribution functions. We first establish that the results of such simulations depend on N for small…

Astrophysics · Physics 2009-11-10 F. Roy , J. Perez

To solve some problems of celestial mechanics and astrophysics, three new models of an elliptical galaxy (EG) have been created, which are in good agreement with modern understanding of the structure of such galaxies. Based on these models,…

Astrophysics of Galaxies · Physics 2023-01-20 S. A. Gasanov

In this abstract paper, we introduce a new kernel learning method by a nonparametric density estimator. The estimator consists of a group of k-centroids clusterings. Each clustering randomly selects data points with randomly selected…

Machine Learning · Computer Science 2017-08-02 Xiao-Lei Zhang

In this work we give new density estimators by averaging classical density estimators such as the histogram, the frequency polygon and the kernel density estimators obtained over different bootstrap samples of the original data. We prove…

Methodology · Statistics 2018-08-24 Mathias Bourel , Jairo Cugliari

The performance of known and new parametric estimators for Archimedean copulas is investigated, with special focus on large dimensions and numerical difficulties. In particular, method-of-moments-like estimators based on pairwise Kendall's…

Computation · Statistics 2012-11-05 Marius Hofert , Martin Maechler , Alexander J. McNeil

We address structured covariance estimation in Elliptical distribution. We assume it is a priori known that the covariance belongs to a given convex set, e.g., the set of Toeplitz or banded matrices. We consider the General Method of…

Statistics Theory · Mathematics 2013-11-05 Ilya Soloveychik , Ami Wiesel

The problem of reducing the bias of maximum likelihood estimator in a general multivariate elliptical regression model is considered. The model is very flexible and allows the mean vector and the dispersion matrix to have parameters in…

Statistics Theory · Mathematics 2016-02-01 Tatiane F. N. Melo , Silvia L. P. Ferrari , Alexandre G. Patriota

Gaussian graphical models (GGMs) are well-established tools for probabilistic exploration of dependence structures using precision matrices. We develop a Bayesian method to incorporate covariate information in this GGMs setup in a nonlinear…

Bayesian methods are a popular choice for statistical inference in small-data regimes due to the regularization effect induced by the prior. In the context of density estimation, the standard nonparametric Bayesian approach is to target the…

Machine Learning · Statistics 2023-02-21 Sahra Ghalebikesabi , Chris Holmes , Edwin Fong , Brieuc Lehmann

The paper deals with planar segment processes given by a density with respect to the Poisson process. Parametric models involve reference distributions of directions and/or lengths of segments. These distributions generally do not coincide…

Statistics Theory · Mathematics 2017-08-30 Viktor Benes , Jakub Vecera , Milan Pultar

This paper proposes multivariate copula models for hierarchical data. They account for two types of correlation: one is between variables measured on the same unit and the other is a correlation between units in the same cluster. This model…

Methodology · Statistics 2023-04-24 Talagbe Gabin Akpo , Louis-Paul Rivest

This article presents factor copula approaches to model temporal dependency of non-Gaussian (continuous/discrete) longitudinal data. Factor copula models are canonical vine copulas which explain the underlying dependence structure of a…

Methodology · Statistics 2025-02-18 Subhajit Chattopadhyay
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