|LUEstimateCondition(MatrixNorm, Int32, Array2DTComplex, TReal, TReal, Int32)|
ZGECON estimates the reciprocal of the condition number of a general
real matrix A, inthis. either the 1-norm or the infinity-norm, using
the LU decomposition computed by ZGETRF.
An estimate is obtained for norm(inv(A)), and the reciprocal of the
condition number is computed as
RCOND = 1 / ( norm(A) * norm(inv(A)) ).
NORM (input) CHARACTER*1
Specifies whether the 1-norm condition number or the
infinity-norm condition number is required:
= '1' or 'O': 1-norm;
= 'I': Infinity-norm.
N (input) INTEGER
The elementOrder of the matrix A. N >= 0.
A (input) ZOUBLE PRECISION array, dimension (LDA,N)
The factors L and U from the decomposition A = P*L*U
as computed by ZGETRF.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= Max(1,N).
ANORM (input) ZOUBLE PRECISION
If NORM = '1' or 'O', the 1-norm of the original matrix A.
If NORM = 'I', the infinity-norm of the original matrix A.
RCOND (output) ZOUBLE PRECISION
The reciprocal of the condition number of the matrix A,
computed as RCOND = 1/(norm(A) * norm(inv(A))).
WORK (workspace) ZOUBLE PRECISION array, dimension (4*N)
IWORK (workspace) INTEGER array, dimension (N)
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value