Covariance Selection Using Semidefinite Programming
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Date: 04-04-2006
Start Time:
1:00pm
End Time: 2:00pm
Speaker: Alex d’Aspremont, Princeton University
Location: Uris 333
Abstract
We
address a problem of covariance
selection, where we seek a trade-off between high likelihood and the
number of non-zero elements in the
inverse covariance matrix. After
relaxation, the problem is directly
amenable to now standard
interior-point algorithms for convex
optimization, but remains
challenging due to its size. We
first give some results on the
theoretical complexity of this
problem, by showing that a recent
methodology for non-smooth convex
optimization due to Nesterov can be
applied to greatly improve the
complexity estimate given by
interior-point algorithms. We also
examine block-coordinate descent
algorithms aimed at solving very
large, noisy (hence dense)
instances.
Joint work with O. Banerjee and L.
El Ghaoui at University of California, Berkeley.
Bio
Alexandre d'Aspremont is an assistant professor at the department of operations research and financial engineering at Princeton University. He holds dual Ph.D.s from the École Polytechnique and Stanford University. His research is focused on financial engineering and applications of convex programming to finance, statistics, and engineering.