Title
Learning the Differential Correlation Matrix of a Smooth Function From Point Samples.
Abstract
Consider an open set $mathbb{D}subseteqmathbb{R}^n$, equipped with a probability measure $mu$. An important characteristic of a smooth function $f:mathbb{D}rightarrowmathbb{R}$ is its $differential$ $correlation$ $matrix$ $Sigma_{mu}:=int nabla f(x) (nabla f(x))^* mu(dx) inmathbb{R}^{ntimes n}$, where $nabla f(x)inmathbb{R}^n$ is the gradient of $f(cdot)$ at $xinmathbb{D}$. For instance, the span of the leading $r$ eigenvectors of $Sigma_{mu}$ forms an $active$ $subspace$ of $f(cdot)$, thereby extending the concept of $principal$ $component$ $analysis$ to the problem of $ridge$ $approximation$. In this work, we propose a simple algorithm for estimating $Sigma_{mu}$ from point values of $f(cdot)$ $without$ imposing any structural assumptions on $f(cdot)$. Theoretical guarantees for this algorithm are provided with the aid of the same technical tools that have proved valuable in the context of covariance matrix estimation from partial measurements.
Year
Venue
Field
2016
arXiv: Information Theory
Mathematical analysis,Covariance matrix,Smoothness,Mathematics
DocType
Volume
Citations 
Journal
abs/1612.06339
0
PageRank 
References 
Authors
0.34
0
4
Name
Order
Citations
PageRank
Armin Eftekhari112912.42
Ping Li232242.76
Michael B. Wakin34299271.57
Rachel Ward422115.52