zgetri (l) - Linux Man Pages
zgetri: computes the inverse of a matrix using the LU factorization computed by ZGETRF
Command to display
zgetri manual in Linux:
$ man l zgetri
ZGETRI - computes the inverse of a matrix using the LU factorization computed by ZGETRF
- SUBROUTINE ZGETRI(
N, A, LDA, IPIV, WORK, LWORK, INFO )
INFO, LDA, LWORK, N
IPIV( * )
A( LDA, * ), WORK( * )
ZGETRI computes the inverse of a matrix using the LU factorization
computed by ZGETRF.
This method inverts U and then computes inv(A) by solving the system
inv(A)*L = inv(U) for inv(A).
- N (input) INTEGER
The order of the matrix A. N >= 0.
- A (input/output) COMPLEX*16 array, dimension (LDA,N)
On entry, the factors L and U from the factorization
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 indices from ZGETRF; for 1<=i<=N, row i of the
matrix was interchanged with row IPIV(i).
- WORK (workspace/output) COMPLEX*16 array, dimension (MAX(1,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.
Pages related to zgetri
- zgetri (3)
- zgetrf (l) - computes an LU factorization of a general M-by-N matrix A using partial pivoting with row interchanges
- zgetrs (l) - solves a system of linear equations A * X = B, A**T * X = B, or A**H * X = B with a general N-by-N matrix A using the LU factorization computed by ZGETRF
- zgetc2 (l) - computes an LU factorization, using complete pivoting, of the n-by-n matrix A
- zgetf2 (l) - computes an LU factorization of a general m-by-n matrix A using partial pivoting with row interchanges
- zgebak (l) - forms the right or left eigenvectors of a complex general matrix by backward transformation on the computed eigenvectors of the balanced matrix output by ZGEBAL
- zgebal (l) - balances a general complex matrix A
- zgebd2 (l) - reduces a complex general m by n matrix A to upper or lower real bidiagonal form B by a unitary transformation