Managed Lapack.Band LUEstimate Condition Method
Definition
Assembly: Extreme.Numerics (in Extreme.Numerics.dll) Version: 8.1.23
Overload List
| Band | Estimates the reciprocal of the condition number of a complex general band matrix A, in either the 1-norm or the infinity-norm, using the LU factorization computed by ZGBTRF. |
| Band | Estimates the reciprocal of the condition number of a real general band matrix A, in either the 1-norm or the infinity-norm, using the LU factorization computed by DGBTRF. |
BandLUEstimateCondition(MatrixNorm, Int32, Int32, Int32, Array2D<Complex<Double>>, Array1D<Int32>, Double, Double, Int32)
Estimates the reciprocal of the condition number of a complex general band matrix A, in either the 1-norm or the infinity-norm, using the LU factorization computed by ZGBTRF.
public override void BandLUEstimateCondition(
MatrixNorm norm,
int n,
int kl,
int ku,
Array2D<Complex<double>> ab,
Array1D<int> ipiv,
double anorm,
out double rcond,
out int info
)Parameters
- norm MatrixNorm
Specifies whether the 1-norm condition number or the infinity-norm condition number is required: = '1' or 'O': 1-norm; = 'I': Infinity-norm.- n Int32
The order of the matrix A. N >= 0.- kl Int32
The number of subdiagonals within the band of A. KL >= 0.- ku Int32
The number of superdiagonals within the band of A. KU >= 0.- ab Array2D<Complex<Double>>
Dimension (LDAB,N) Details of the LU factorization of the band matrix A, as computed by ZGBTRF. U is stored as an upper triangular band matrix with KL+KU superdiagonals in rows 1 to KL+KU+1, and the multipliers used during the factorization are stored in rows KL+KU+2 to 2*KL+KU+1.The leading dimension of the array AB. LDAB >= 2*KL+KU+1.- ipiv Array1D<Int32>
Dimension (N) The pivot indices; for 1 <= i <= N, row i of the matrix was interchanged with row IPIV(i).- anorm Double
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 Double
The reciprocal of the condition number of the matrix A, computed as RCOND = 1/(norm(A) * norm(inv(A))).- info Int32
= 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value
Remarks
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)) ).
BandLUEstimateCondition(MatrixNorm, Int32, Int32, Int32, Array2D<Double>, Array1D<Int32>, Double, Double, Int32)
Estimates the reciprocal of the condition number of a real general band matrix A, in either the 1-norm or the infinity-norm, using the LU factorization computed by DGBTRF.
public override void BandLUEstimateCondition(
MatrixNorm norm,
int n,
int kl,
int ku,
Array2D<double> ab,
Array1D<int> ipiv,
double anorm,
out double rcond,
out int info
)Parameters
- norm MatrixNorm
Specifies whether the 1-norm condition number or the infinity-norm condition number is required: = '1' or 'O': 1-norm; = 'I': Infinity-norm.- n Int32
The order of the matrix A. N >= 0.- kl Int32
The number of subdiagonals within the band of A. KL >= 0.- ku Int32
The number of superdiagonals within the band of A. KU >= 0.- ab Array2D<Double>
Dimension (LDAB,N) Details of the LU factorization of the band matrix A, as computed by DGBTRF. U is stored as an upper triangular band matrix with KL+KU superdiagonals in rows 1 to KL+KU+1, and the multipliers used during the factorization are stored in rows KL+KU+2 to 2*KL+KU+1.The leading dimension of the array AB. LDAB >= 2*KL+KU+1.- ipiv Array1D<Int32>
Dimension (N) The pivot indices; for 1 <= i <= N, row i of the matrix was interchanged with row IPIV(i).- anorm Double
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 Double
The reciprocal of the condition number of the matrix A, computed as RCOND = 1/(norm(A) * norm(inv(A))).- info Int32
= 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value
Remarks
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)) ).
This method corresponds to the LAPACK routine DGBCON.