You are here: MIMS > EPrints
MIMS EPrints

2015.40: Computing Nearest Covariance and Correlation Matrices

2015.40: Craig Lucas (2001) Computing Nearest Covariance and Correlation Matrices. Masters thesis, Manchester Institute for Mathematical Sciences, The University of Manchester.

Full text available as:

PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
384 Kb


We look at two matrix nearness problems posed by a finance company, where nearness is measured in the Frobenius norm. Correlation and covariance matrices are computed from sampled stock data with missing entries by a technique that produces matrices that are not positive semidefinite. In the first problem we find the nearest correlation matrix that is positive semidefinite and preserves any correlations known to be exact. In the second problem we investigate how the missing elements in the data should be chosen in order to generate the nearest covariance matrix to the indefinite matrix from the completed set of data. We show how the former problem can be solved using an alternating projections algorithm and how the latter problem can be investigated using a multi-directional search optimization method.

Item Type:Thesis (Masters)
Uncontrolled Keywords:nearest positive semidefinite correlation covariance matrices
Subjects:MSC 2000 > 15 Linear and multilinear algebra; matrix theory
MSC 2000 > 65 Numerical analysis
MIMS number:2015.40
Deposited By:Dr Craig Lucas
Deposited On:11 June 2015

Download Statistics: last 4 weeks
Repository Staff Only: edit this item