Title
Sample complexity of Bayesian optimal dictionary learning
Abstract
We consider a learning problem of identifying a dictionary matrix D ∈ RM×N from a sample set of M dimensional vectors Y ∈ RM×P = N-1/2DX ∈ RM×P, where X ∈ RN×p is a sparse matrix in which the density of non-zero entries is 0 <; ρ <; 1. In particular, we focus on the minimum sample size Pc (sample complexity) necessary for perfectly identifying D of the optimal learning scheme when D and X are independently generated from certain distributions. By using the replica method of statistical mechanics, we show that Pc ~ O(N) holds as long as α = M/N > ρ is satisfied in the limit of N → ∞. Our analysis also implies that the posterior distribution given Y is condensed only at the correct dictionary D when the compression rate α is greater than a certain critical value αM(p). This suggests that belief propagation may allow us to learn D with a low computational complexity using O(N) samples.
Year
DOI
Venue
2013
10.1109/ISIT.2013.6620310
international symposium on information theory
Keywords
Field
DocType
Bayes methods,computational complexity,learning (artificial intelligence),sparse matrices,statistical mechanics,vectors,Bayesian optimal dictionary learning,M dimensional vectors,compression rate,dictionary matrix identification,nonzero entry density,posterior distribution,replica method,sample complexity,sparse matrix,sparse representations,statistical mechanics
Information theory,Discrete mathematics,Combinatorics,Data compression ratio,Computer science,Matrix (mathematics),Posterior probability,Sparse matrix,Computational complexity theory,Bayesian probability,Belief propagation
Journal
Volume
ISSN
Citations 
abs/1301.6199
2157-8095
3
PageRank 
References 
Authors
0.45
5
2
Name
Order
Citations
PageRank
Ayaka Sakata1243.93
Yoshiyuki Kabashima213627.83