Search Results for author: Joel A. Tropp

Found 19 papers, 8 papers with code

Robust, randomized preconditioning for kernel ridge regression

1 code implementation24 Apr 2023 Mateo Díaz, Ethan N. Epperly, Zachary Frangella, Joel A. Tropp, Robert J. Webber

This paper introduces two randomized preconditioning techniques for robustly solving kernel ridge regression (KRR) problems with a medium to large number of data points ($10^4 \leq N \leq 10^7$).

regression

Efficient error and variance estimation for randomized matrix computations

no code implementations13 Jul 2022 Ethan N. Epperly, Joel A. Tropp

Randomized matrix algorithms have become workhorse tools in scientific computing and machine learning.

Randomly pivoted Cholesky: Practical approximation of a kernel matrix with few entry evaluations

1 code implementation13 Jul 2022 Yifan Chen, Ethan N. Epperly, Joel A. Tropp, Robert J. Webber

The randomly pivoted partial Cholesky algorithm (RPCholesky) computes a factorized rank-k approximation of an N x N positive-semidefinite (psd) matrix.

Learning to Forecast Dynamical Systems from Streaming Data

1 code implementation20 Sep 2021 Dimitris Giannakis, Amelia Henriksen, Joel A. Tropp, Rachel Ward

This algorithm dramatically reduces the costs of training and prediction without sacrificing forecasting skill.

regression Time Series +1

Tensor Random Projection for Low Memory Dimension Reduction

no code implementations30 Apr 2021 Yiming Sun, Yang Guo, Joel A. Tropp, Madeleine Udell

The TRP map is formed as the Khatri-Rao product of several smaller random projections, and is compatible with any base random projection including sparse maps, which enable dimension reduction with very low query cost and no floating point operations.

Dimensionality Reduction

Inference of Black Hole Fluid-Dynamics From Sparse Interferometric Measurements

no code implementations ICCV 2021 Aviad Levis, Daeyoung Lee, Joel A. Tropp, Charles F. Gammie, Katherine L. Bouman

We are motivated by the task of imaging the stochastically evolving environment surrounding black holes, and demonstrate how flow parameters can be estimated from sparse interferometric measurements used in radio astronomical imaging.

Concentration for random product formulas

no code implementations26 Aug 2020 Chi-Fang Chen, Hsin-Yuan Huang, Richard Kueng, Joel A. Tropp

qDRIFT achieves a gate count that does not explicitly depend on the number of terms in the Hamiltonian, which contrasts with Suzuki formulas.

Quantum Physics Probability

An Optimal-Storage Approach to Semidefinite Programming using Approximate Complementarity

no code implementations9 Feb 2019 Lijun Ding, Alp Yurtsever, Volkan Cevher, Joel A. Tropp, Madeleine Udell

This paper develops a new storage-optimal algorithm that provably solves generic semidefinite programs (SDPs) in standard form.

Fixed-Rank Approximation of a Positive-Semidefinite Matrix from Streaming Data

no code implementations NeurIPS 2017 Joel A. Tropp, Alp Yurtsever, Madeleine Udell, Volkan Cevher

Several important applications, such as streaming PCA and semidefinite programming, involve a large-scale positive-semidefinite (psd) matrix that is presented as a sequence of linear updates.

Practical sketching algorithms for low-rank matrix approximation

no code implementations31 Aug 2016 Joel A. Tropp, Alp Yurtsever, Madeleine Udell, Volkan Cevher

This paper describes a suite of algorithms for constructing low-rank approximations of an input matrix from a random linear image of the matrix, called a sketch.

Universality laws for randomized dimension reduction, with applications

no code implementations30 Nov 2015 Samet Oymak, Joel A. Tropp

In the Euclidean setting, one fundamental technique for dimension reduction is to apply a random linear map to the data.

Dimensionality Reduction

An Introduction to Matrix Concentration Inequalities

1 code implementation7 Jan 2015 Joel A. Tropp

In recent years, random matrices have come to play a major role in computational mathematics, but most of the classical areas of random matrix theory remain the province of experts.

Time--Data Tradeoffs by Aggressive Smoothing

no code implementations NeurIPS 2014 John J. Bruer, Joel A. Tropp, Volkan Cevher, Stephen Becker

This paper proposes a tradeoff between sample complexity and computation time that applies to statistical estimators based on convex optimization.

Paved with Good Intentions: Analysis of a Randomized Block Kaczmarz Method

no code implementations19 Aug 2012 Deanna Needell, Joel A. Tropp

The block Kaczmarz method is an iterative scheme for solving overdetermined least-squares problems.

Numerical Analysis Numerical Analysis 65F10, 65F20, 68W20, 41A65

Factoring nonnegative matrices with linear programs

1 code implementation NeurIPS 2012 Victor Bittorf, Benjamin Recht, Christopher Re, Joel A. Tropp

The constraints are chosen to ensure that the matrix C selects features; these features can then be used to find a low-rank NMF of X.

Robust computation of linear models by convex relaxation

no code implementations18 Feb 2012 Gilad Lerman, Michael McCoy, Joel A. Tropp, Teng Zhang

Consider a dataset of vector-valued observations that consists of noisy inliers, which are explained well by a low-dimensional subspace, along with some number of outliers.

Improved analysis of the subsampled randomized Hadamard transform

1 code implementation6 Nov 2010 Joel A. Tropp

This paper presents an improved analysis of a structured dimension-reduction map called the subsampled randomized Hadamard transform.

Numerical Analysis Data Structures and Algorithms Probability 15B52

Finding structure with randomness: Probabilistic algorithms for constructing approximate matrix decompositions

10 code implementations22 Sep 2009 Nathan Halko, Per-Gunnar Martinsson, Joel A. Tropp

These methods use random sampling to identify a subspace that captures most of the action of a matrix.

Numerical Analysis Probability

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