MATLAB Functions Help Desk

rcond

Purpose

Matrix reciprocal condition number estimate

Syntax

c = rcond(A)

Description

c = rcond(A) returns an estimate for the reciprocal of the condition of A in
1-norm using the LINPACK 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

The rcond function uses the condition estimator from the LINPACK routine ZGECO.

See Also

cond

Condition number with respect to inversion

condest

1-norm matrix condition number estimate

norm

Vector and matrix norms

normest

2-norm estimate

rank

Rank of a matrix

svd

Singular value decomposition

References

[1] Dongarra, J.J., J.R. Bunch, C.B. Moler, and G.W. Stewart, LINPACK
Users' Guide, SIAM, Philadelphia, 1979.



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