English
Related papers

Related papers: Sparse Functional Boxplots for Multivariate Curves

200 papers

In functional data analysis, functional linear regression has attracted significant attention recently. Herein, we consider the case where both the response and covariates are functions. There are two available approaches for addressing…

Methodology · Statistics 2021-09-28 Mauro Bernardi , Antonio Canale , Marco Stefanucci

To detect differences between the mean curves of two samples in longitudinal study or functional data analysis, we usually need to partition the temporal or spatial domain into several pre-determined sub-areas. In this paper we apply the…

Methodology · Statistics 2015-05-01 Peirong Xu , Youngjo Lee , Jian Qing Shi

Recent advances in engineering technologies have enabled the collection of a large number of longitudinal features. This wealth of information presents unique opportunities for researchers to investigate the complex nature of diseases and…

Methodology · Statistics 2023-11-27 Zihang Lu , Noirrit Kiran Chandra

We develop a novel methodology for detecting abrupt break points in mean functions of functional time series, adaptable to arbitrary sampling schemes. By employing B-spline smoothing, we introduce $\mathcal L_{\infty}$ and $\mathcal L_2$…

Methodology · Statistics 2024-12-31 Leheng Cai , Qirui Hu

This paper focuses on the analysis of spatially correlated functional data. The between-curve correlation is modeled by correlating functional principal component scores of the functional data. We propose a Spatial Principal Analysis by…

Statistics Theory · Mathematics 2014-11-19 Chong Liu , Surajit Ray , Giles Hooker

Testing the homogeneity between two samples of functional data is an important task. While this is feasible for intensely measured functional data, we explain why it is challenging for sparsely measured functional data and show what can be…

Methodology · Statistics 2022-07-05 Changbo Zhu , Jane-Ling Wang

We consider inference for the mean and covariance functions of covariate adjusted functional data using Local Linear Kernel (LLK) estimators. By means of a double asymptotic, we differentiate between sparse and dense covariate adjusted…

Methodology · Statistics 2018-02-28 Dominik Liebl

Functional data that are nonnegative and have a constrained integral can be considered as samples of one-dimensional density functions. Such data are ubiquitous. Due to the inherent constraints, densities do not live in a vector space and,…

Statistics Theory · Mathematics 2016-01-13 Alexander Petersen , Hans-Georg Müller

In several environmental applications data are functions of time, essentially con- tinuous, observed and recorded discretely, and spatially correlated. Most of the methods for analyzing such data are extensions of spatial statistical tools…

Methodology · Statistics 2011-06-28 Elvira Romano , Antonio Balzanella , Rosanna Verde

The bagplot, also known as the "bag-and-bolster plot", is a notable extension of the boxplot from univariate to bivariate data. Although widely used, its practical application is hindered by two key limitations: the fixed inflation factor…

Methodology · Statistics 2025-12-09 Shenghao Qin , Bowen Gang , Tiejun Tong , Hengjian Cui

Recent research has focused on weight sparsity in deep neural network training to reduce FLOPs, aiming for improved efficiency (test accuracy w.r.t training FLOPs). However, sparse weight training often compromises accuracy, requiring…

Machine Learning · Computer Science 2024-07-19 Vithursan Thangarasa , Shreyas Saxena , Abhay Gupta , Sean Lie

Sparse coding has been popularly used as an effective data representation method in various applications, such as computer vision, medical imaging and bioinformatics, etc. However, the conventional sparse coding algorithms and its manifold…

Computer Vision and Pattern Recognition · Computer Science 2013-04-04 Jing-Yan Wang

A nearly optimal explicitly-sparse representation for oscillatory kernels is presented in this work by developing a curvelet based method. Multilevel curvelet-like functions are constructed as the transform of the original nodal basis. Then…

Numerical Analysis · Mathematics 2025-04-29 Yanchuang Cao , Jun Liu , Dawei Chen

Image data are increasingly encountered and are of growing importance in many areas of science. Much of these data are quantitative image data, which are characterized by intensities that represent some measurement of interest in the…

Multiscale phenomena that evolve on multiple distinct timescales are prevalent throughout the sciences. It is often the case that the governing equations of the persistent and approximately periodic fast scales are prescribed, while the…

Chaotic Dynamics · Physics 2020-08-19 Jason J. Bramburger , Daniel Dylewsky , J. Nathan Kutz

Regularized variants of Principal Components Analysis, especially Sparse PCA and Functional PCA, are among the most useful tools for the analysis of complex high-dimensional data. Many examples of massive data, have both sparse and…

Machine Learning · Statistics 2019-08-21 Genevera I. Allen , Michael Weylandt

This paper addresses the fundamental task of estimating covariance matrix functions for high-dimensional functional data/functional time series. We consider two functional factor structures encompassing either functional factors with scalar…

Methodology · Statistics 2025-10-28 Dong Li , Xinghao Qiao , Zihan Wang

In this paper we develop a novel approach for estimating large and sparse dynamic factor models using variational inference, also allowing for missing data. Inspired by Bayesian variable selection, we apply slab-and-spike priors onto the…

Methodology · Statistics 2022-10-14 Erik Spånberg

We consider a novel Bayesian approach to estimation, uncertainty quantification, and variable selection for a high-dimensional linear regression model under sparsity. The number of predictors can be nearly exponentially large relative to…

Methodology · Statistics 2025-02-28 Samhita Pal , Subhashis Ghoshal

This article inspects whether a multivariate distribution is different from a specified distribution or not, and it also tests the equality of two multivariate distributions. In the course of this study, a graphical tool-kit using…

Methodology · Statistics 2024-08-19 Pratim Guha Niyogi , Subhra Sankar Dhar