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Approximating a Symmetric Matrix

Published online by Cambridge University Press:  01 January 2025

R. A. Bailey
Affiliation:
Statistics Department, Rothamsted Experimental Station
J. C. Gower*
Affiliation:
Statistics Department, Rothamsted Experimental Station
*
Requests for reprints should be sent to J. C. Gower, Statistics Department, Rothamsted Experimental Station, Harpenden, Herts, AL5 2JQ, United Kingdom.

Abstract

We examine the least squares approximation C to a symmetric matrix B, when all diagonal elements get weight w relative to all nondiagonal elements. WhenB has positivity p and C is constrained to be positive semi-definite, our main result states that, when w ≥1/2, then the rank of C is never greater than p, and when w ≤1/2 then the rank of C is at least p. For the problem of approximating a given n × n matrix with a zero diagonal by a squared-distance matrix, it is shown that the sstress criterion leads to a similar weighted least squares solution with w =(n+2)/4; the main result remains true. Other related problems and algorithmic consequences are briefly discussed.

Type
Original Paper
Copyright
Copyright © 1990 The Psychometric Society

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References

Browne, M. W. (1987). The Young-Householder alogrithm and the least-squares multidimensional scaling of squared distances. Journal of Classification, 4, 175190.CrossRefGoogle Scholar
Critchley, F. (1986). Dimensionality theorems in multidimensional scaling and hierarchical cluster analysis. In Diday, E., Escoufier, Y., Lebart, L., Lepage, J., Schektman, Y., & Tomassone, R. (Eds.), Informatics, IV (pp. 85110). Ansterdam: North-Holland.Google Scholar
de Leeuw, J. (1975). An alternating least squares approach to squared distance scaling. Unpublished manuscript, University of Leiden, Department of Data Theory.Google Scholar
de Leeuw, J., & Heiser, W. (1982). Theory of multidimensional scaling. In Krishnaish, P. R., & Kanal, L. N. (Eds.), Handbook of statistics, Volume 2, Classification pattern recognition and reduction of dimensionality (pp. 285316). Amsterdam: North-Holland.CrossRefGoogle Scholar
Dijkstra, T. K. (1990). Some properties estimated scale invariant covariance structures. Psychometrika, 55, 327336.CrossRefGoogle Scholar
Eckart, C., & Young, G. (1936). The approximation of one matrix by another of lower rank. Psychometrika, 1, 211218.CrossRefGoogle Scholar
Gower, J. C. (1977). The analysis of asymmetry and orthogonality. In Barra, J. R., Brodeau, F., Romier, G. & van Cutsem, B. (Eds.), Recent developments in statistics (pp. 109123). Amsterdam: North-Holland.Google Scholar
Gower, J. C. (1982). Euclidean distance geometry. The Mathematical Scientist, 7, 114.Google Scholar
Gower, J. C. (1984). Distance matrices and their Euclidean approximation. In Diday, E., Jambu, M., Lebart, L., Pagès, J., & Tomassone, R. (Eds.), Data analysis and informatics, III (pp. 321). Amsterdam: North-Holland.Google Scholar
Kreider, D. L., Kuller, R. G., & Ostberg, D. R., Perkins, F. W. (1966). An introduction to linear analysis, Reading, MA: Addison Wesley.Google Scholar
Takane, Y. (1977). On the relations among four methods of multidimensional scaling. Behaviormetrika, 4, 2943.CrossRefGoogle Scholar
Takane, Y., Young, F., & de Leeuw, J. (1976). Nonmetric individual differences multidimensional scaling: an alternative least squares method with optimal scaling features. Psychometria, 42, 767.CrossRefGoogle Scholar
Wilkinson, J. H. (1965). The algebraic eigenvalue problem, Oxford: Oxford University Press.Google Scholar