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riccond    See Also

Condition numbers of continuous algebraic Riccati equation.

Syntax

Description

Riccond provides the condition numbers of continuous Riccati equation. The input variable qrn contains the weighting matrix

for the Riccati equation

where P = P2/P1 is the positive definite solution of ARE, and [P2; P1] spans the stable eigenspace of the Hamiltonian

Several measurements are provided:

The output variable tot puts the above measurements in a column vector

For an ill-conditioned problem, one or more of the above measurements could become large. Together, these measurements give a general sense of the Riccati problem conditioning issues.

Algorithm

Arnold and Laub's Riccati condition number is computed as follows [1]:

where Acl = Ac - RcP and

Byers' Riccati condition number is computed as [2]

See Also

are, aresolv, daresolv, driccond

References

[1] W. F. Arnold, III and A. Laub, "Generalized Eigenproblem Algorithms and Software for Algebraic Riccati Equations," Proceedings of the IEEE, Vol. 72, No. 12, Dec. 1984.

[2] R. Byers, "Hamiltonian and Symplectic Algorithms for the Algebraic Riccati Equation," Ph.D. dissertation, Dept. of Comp. Sci., Cornell University, Ithaca, NY, 1983.



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