Generic Decomposition Operations<T>.Symmetric Estimate Condition Method
Definition
Assembly: Numerics.NET.Generic (in Numerics.NET.Generic.dll) Version: 9.0.3
Overload List
Symmetric | Estimates the reciprocal of the condition number (in the 1-norm) of a real symmetric matrix A using the factorization A = U*D*UT or A = L*D*LT computed by DSYTRF. |
Symmetric | Estimates the reciprocal of the condition number (in the 1-norm) of a real symmetric matrix A using the factorization A = U*D*UT or A = L*D*LT computed by DSYTRF. |
Symmetric | Estimates the reciprocal of the condition number (in the 1-norm) of a real symmetric matrix A using the factorization A = U*D*UT or A = L*D*LT computed by DSYTRF. |
SymmetricEstimateCondition(MatrixTriangle, Int32, ReadOnlySpan<T>, Int32, ReadOnlySpan<Int32>, T, T, Int32)
Estimates the reciprocal of the condition number (in the 1-norm) of a real symmetric matrix A using the factorization A = U*D*UT or A = L*D*LT computed by DSYTRF.
public override void SymmetricEstimateCondition(
MatrixTriangle storedTriangle,
int n,
ReadOnlySpan<T> a,
int lda,
ReadOnlySpan<int> ipiv,
T anorm,
out T rcond,
out int info
)
Parameters
- storedTriangle MatrixTriangle
Specifies whether the details of the factorization are stored as an upper or lower triangular matrix. = 'U': Upper triangular, form is A = U*D*UT; = 'L': Lower triangular, form is A = L*D*LT.
- n Int32
The order of the matrix A. N >= 0.
- a ReadOnlySpan<T>
A is TReal array, dimension (LDA,N) The block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by DSYTRF.
- lda Int32
The leading dimension of the array A. LDA >= max(1,N).
- ipiv ReadOnlySpan<Int32>
Dimension (N) Details of the interchanges and the block structure of D as determined by DSYTRF.
- anorm T
ANORM is TReal The 1-norm of the original matrix A.
- rcond T
RCOND is TReal The reciprocal of the condition number of the matrix A, computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is an estimate of the 1-norm of inv(A) computed in this routine.
- 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 / (ANORM * norm(inv(A))).
This method corresponds to the LAPACK routine ?SYCON.