Abstract
We consider the parameter space of all the linear inequality systems, in the n-dimensional Euclidean space and with a fixed index set, endowed with the topology of the uniform convergence of the coefficient vectors. A system is ill-posed with respect to the consistency when arbitrarily small perturbations yield both consistent and inconsistent systems. In this paper, we establish a formula for measuring the distance from the nominal system to the set of ill-posed systems. To this aim, we use the Fenchel-Legendre conjugation theory and prove a refinement of the formula in Ref. 1 for the distance from any point to the boundary of a convex set.
Similar content being viewed by others
References
COULIBALY, A., and CROUZEIX, J. P., On the Conditioning of a Convex Set and Its Representations, Unpublished Manuscript, 2002.
EPELMAN, M., and FREUND, R.M., Condition Number Complexity of an Elementary Algorithm for Computing a Reliable Solution of a Conic Linear System, Mathematical Programming, Vol. 88A, pp. 451–485, 2000.
FREUND, R.M., and VERA, J.R., Some Characterizations and Properties of the Distance to Ill-Posedness and the Condition Measure of a Conic Linear System, Mathematical Programming, Vol. 86A, pp. 225–260, 1999.
RENEGAR, J., Some Perturbation Theory for Linear Programming, Mathematical Programming, Vol. 65A, pp. 73–91, 1994.
ROCKAFELLAR, R.T., Convex Analysis, Princeton University Press, Princetion, New Jersey, 1970.
HIRIART-URRUTY, J.B., and LEMARECHAL, C. Convex Analysis and Minimization Algorithms, Vols. 1 and 2, Springer-Verlag, New York, NY, 1993.
GINCHEV, I., and HOFFMANN, A., Approximation of Set-Valued Functions by Single-Valued Ones, Discussions Mathematicae: Differential Inclusions, Control, and Optimizations, Vol. 22, pp. 33–66, 2002.
HIRIART-URRUTY, J.B., New Concepts in Nondifferentiable Programming, Bulletin de la Société Mathématique de France, Vol. 60, pp. 57–85, 1979.
HIRIART-URRUTY, J.B., Tangent Cones, Generalized Gradients, and Mathematical Programming in Banach Spaces, Mathematics of Operations Research, Vol. 4, pp. 79–97, 1979.
Zu, Y.J., Generalizations of Some Fundamental Theorems on Linear Inequalities, Acta Mathematica Sinica, Vol. 16, pp. 25–40, 1966.
CÁNOVAS, M.J., LÓPEZ, M.A., PARRA, J., and TOLEDO, F.J., Distance to Ill-Posedness and the Consistency Value of Linear Semi-Inifinite Inequality Systems, Mathematical Programming, Vol. 103A, pp. 95–126, 2005.
CÁNOVAS, M.J., LÓPEZ, M.A., PARRA, J., TOLEDO, F.J., Distance to Solvability/Unsolvability in Linear Optimizations, SIAM Journal on Optimization, Vol. 16, pp. 629-649, 2006.
RENEGAR, J., Linear Programming, Complexity Theory, and Elementary Functional Analysis, Mathematical Programming, Vol. 70A, pp. 279–351, 1995.
Author information
Authors and Affiliations
Additional information
Communicated by J.P. Crouzeix
This research has been partially supported by grants BFM2002–04114-C02 (01–02) from MEC (Spain) and FEDER (EU) and by grants GV04B-648 and GRUPOS04/79 from Generalitat Valenciana (Spain).
Rights and permissions
About this article
Cite this article
Cánovas, M.J., López, M.A., Parra, J. et al. Distance to Ill-Posedness in Linear Optimization via the Fenchel-Legendre Conjugate. J Optim Theory Appl 130, 173–183 (2006). https://doi.org/10.1007/s10957-006-9097-5
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10957-006-9097-5