Convex relaxations of structured matrix factorizations. Bach, F.
Convex relaxations of structured matrix factorizations [link]Paper  abstract   bibtex   
We consider the factorization of a rectangular matrix $X $ into a positive linear combination of rank-one factors of the form $u v{\textasciicircum}{\}top$, where $u$ and $v$ belongs to certain sets ${\}mathcal\{U\}$ and ${\}mathcal\{V\}$, that may encode specific structures regarding the factors, such as positivity or sparsity. In this paper, we show that computing the optimal decomposition is equivalent to computing a certain gauge function of $X$ and we provide a detailed analysis of these gauge functions and their polars. Since these gauge functions are typically hard to compute, we present semi-definite relaxations and several algorithms that may recover approximate decompositions with approximation guarantees. We illustrate our results with simulations on finding decompositions with elements in ${\}\{0,1{\}\}$. As side contributions, we present a detailed analysis of variational quadratic representations of norms as well as a new iterative basis pursuit algorithm that can deal with inexact first-order oracles.
@misc{bach-arxiv13,
	title = {Convex relaxations of structured matrix factorizations},
	url = {http://arxiv.org/abs/1309.3117},
	abstract = {We consider the factorization of a rectangular matrix \$X \$ into a positive linear combination of rank-one factors of the form \$u v{\textasciicircum}{\textbackslash}top\$, where \$u\$ and \$v\$ belongs to certain sets \${\textbackslash}mathcal\{U\}\$ and \${\textbackslash}mathcal\{V\}\$, that may encode specific structures regarding the factors, such as positivity or sparsity. In this paper, we show that computing the optimal decomposition is equivalent to computing a certain gauge function of \$X\$ and we provide a detailed analysis of these gauge functions and their polars. Since these gauge functions are typically hard to compute, we present semi-definite relaxations and several algorithms that may recover approximate decompositions with approximation guarantees. We illustrate our results with simulations on finding decompositions with elements in \${\textbackslash}\{0,1{\textbackslash}\}\$. As side contributions, we present a detailed analysis of variational quadratic representations of norms as well as a new iterative basis pursuit algorithm that can deal with inexact first-order oracles.},
	number = {{arXiv}:1309.3117},
	publisher = {{arXiv}},
	author = {Bach, Francis},
	urldate = {2024-01-16},
	date = {2013-09-12},
	eprinttype = {arxiv},
	eprint = {1309.3117 [cs, math]},
	keywords = {Computer Science - Machine Learning, Mathematics - Optimization and Control},
	file = {arXiv.org Snapshot:/Users/ukreddy/Zotero/storage/BWLAY4CW/1309.html:text/html;Full Text PDF:/Users/ukreddy/Zotero/storage/34TL4VEA/Bach - 2013 - Convex relaxations of structured matrix factorizat.pdf:application/pdf},
}

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