Decomposition Operations<TReal, TComplex>.LUInvert Method
Definition
Namespace: Extreme.Mathematics.LinearAlgebra.Implementation
Assembly: Extreme.Numerics (in Extreme.Numerics.dll) Version: 8.1.23
Assembly: Extreme.Numerics (in Extreme.Numerics.dll) Version: 8.1.23
Overload List
LUInvert( | Computes the inverse of a matrix using the LU decomposition computed by LUDecompose(Int32, Int32, Array2D<TReal>, Array1D<Int32>, Int32). |
LUInvert( | ZGETRI computes the inverse of a matrix using the LU decomposition computed by ZGETRF. This method inverts U and then computes inv(A) by solving the system inv(A)*L = inv(U) for inv(A). Arguments ========= N (input) INTEGER The elementOrder of the matrix A. N >= 0. A (input/output) ZOUBLE PRECISION array, dimension (LDA,N) On entry, the factors L and U from the decomposition A = P*L*U as computed by ZGETRF. On exit, if INFO = 0, the inverse of the original matrix A. LDA (input) INTEGER The leading dimension of the array A. LDA >= Max(1,N). IPIV (input) INTEGER array, dimension (N) The pivot indexes from ZGETRF; for 1< =i< =N, row i of the matrix was interchanged with row IPIVi. WORK (workspace/output) ZOUBLE PRECISION array, dimension (LWORK) On exit, if INFO =0, then WORK(1) returns the optimal LWORK. LWORK (input) INTEGER The dimension of the array WORK. LWORK >= Max(1,N). For optimal performance LWORK >= N*NB, where NB is the optimal blocksize returned by ILAENV. If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument had an illegal value > 0: if INFO = i, U(i,i) is exactly zero; the matrix is singular and its inverse could not be computed. |
LUInvert(Int32, Array2D<TReal>, Array1D<Int32>, Int32)
Computes the inverse of a matrix using the LU decomposition
computed by LUDecompose(Int32, Int32, Array2D<TReal>, Array1D<Int32>, Int32).
public abstract void LUInvert(
int n,
Array2D<TReal> a,
Array1D<int> ipiv,
out int info
)
Parameters
- n Int32
- An integer specifying the number of rows and columns of the matrix a. Must be greater than or equal to zero.
- a Array2D<TReal>
- TReal array specifying the n-by-n matrix containing the lower and upper triangular factors as computed by LUDecompose(Int32, Int32, Array2D<TReal>, Array1D<Int32>, Int32).
- ipiv Array1D<Int32>
- Integer array that contains the pivot indexes computed by LUDecompose(Int32, Int32, Array2D<TReal>, Array1D<Int32>, Int32).
- info Int32
- Reference to an integer containing a result code. Zero indicates success. Greater than zero indicates U(i,i) is exactly zero. The matrix is singular and its inverse could not be computed.
LUInvert(Int32, Array2D<TComplex>, Array1D<Int32>, Int32)
ZGETRI computes the inverse of a matrix using the LU decomposition
computed by ZGETRF.
This method inverts U and then computes inv(A) by solving the system
inv(A)*L = inv(U) for inv(A).
Arguments
=========
N (input) INTEGER
The elementOrder of the matrix A. N >= 0.
A (input/output) ZOUBLE PRECISION array, dimension (LDA,N)
On entry, the factors L and U from the decomposition
A = P*L*U as computed by ZGETRF.
On exit, if INFO = 0, the inverse of the original matrix A.
LDA (input) INTEGER
The leading dimension of the array A. LDA >= Max(1,N).
IPIV (input) INTEGER array, dimension (N)
The pivot indexes from ZGETRF; for 1< =i< =N, row i of the
matrix was interchanged with row IPIVi.
WORK (workspace/output) ZOUBLE PRECISION array, dimension (LWORK)
On exit, if INFO =0, then WORK(1) returns the optimal LWORK.
LWORK (input) INTEGER
The dimension of the array WORK. LWORK >= Max(1,N).
For optimal performance LWORK >= N*NB, where NB is
the optimal blocksize returned by ILAENV.
If LWORK = -1, then a workspace query is assumed; the routine
only calculates the optimal size of the WORK array, returns
this value as the first entry of the WORK array, and no error
message related to LWORK is issued by XERBLA.
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value
> 0: if INFO = i, U(i,i) is exactly zero; the matrix is
singular and its inverse could not be computed.
public abstract void LUInvert(
int n,
Array2D<TComplex> a,
Array1D<int> ipiv,
out int info
)