MATLAB Function Reference    
rcond

Matrix reciprocal condition number estimate

Syntax

Description

c = rcond(A) returns an estimate for the reciprocal of the condition of A in 1-norm using the LAPACK condition estimator. If A is well conditioned, rcond(A) is near 1.0. If A is badly conditioned, rcond(A) is near 0.0. Compared to cond, rcond is a more efficient, but less reliable, method of estimating the condition of a matrix.

Algorithm

rcond uses LAPACK routines to compute the estimate of the reciprocal condition number:

Matrix
 Routine
Real
 DLANGE, DGETRF, DGECON
Complex
 ZLANGE, ZGETRF, ZGECON

See Also

cond, condest, norm, normest, rank, svd

References

[1]  Anderson, E., Z. Bai, C. Bischof, S. Blackford, J. Demmel, J. Dongarra, J. Du Croz, A. Greenbaum, S. Hammarling, A. McKenney, and D. Sorensen, LAPACK User's Guide (http://www.netlib.org/lapack/lug/ lapack_lug.html), Third Edition, SIAM, Philadelphia, 1999.


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