Generic Decomposition Operations<T>.Symmetric Invert Method
Computes the inverse of a real symmetric indefinite matrix A using the factorization A = U*D*UT or A = L*D*LT computed by DSYTRF.
Definition
Namespace: Extreme.Mathematics.LinearAlgebra.Implementation
Assembly: Extreme.Numerics.Generic (in Extreme.Numerics.Generic.dll) Version: 8.1.4
C#
Assembly: Extreme.Numerics.Generic (in Extreme.Numerics.Generic.dll) Version: 8.1.4
public override void SymmetricInvert(
MatrixTriangle storedTriangle,
int n,
Array2D<T> a,
Array1D<int> ipiv,
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 Array2D<T>
Dimension (LDA,N) On entry, the block diagonal matrix D and the multipliers used to obtain the factor U or L as computed by DSYTRF. On exit, if info = 0, the (symmetric) inverse of the original matrix. If UPLO = 'U', the upper triangular part of the inverse is formed and the part of A below the diagonal is not referenced; if UPLO = 'L' the lower triangular part of the inverse is formed and the part of A above the diagonal is not referenced.
The leading dimension of the array A. LDA >= max(1,N).
- ipiv Array1D<Int32>
Dimension (N) Details of the interchanges and the block structure of D as determined by DSYTRF.
- info Int32
info is INTEGER = 0: successful exit < 0: if info = -i, the i-th argument had an illegal value > 0: if info = i, D(i,i) = 0; the matrix is singular and its inverse could not be computed.
Remarks
This method corresponds to the LAPACK routine DSYTRI.