ZGESV
November 2006
Purpose
ZGESV computes the solution to a complex system of linear equations
A * X = B,
where A is an N-by-N matrix and X and B are N-by-NRHS matrices.
The LU decomposition with partial pivoting and row interchanges is
used to factor A as
A = P * L * U,
where P is a permutation matrix, L is unit lower triangular, and U is
upper triangular. The factored form of A is then used to solve the
system of equations A * X = B.
A * X = B,
where A is an N-by-N matrix and X and B are N-by-NRHS matrices.
The LU decomposition with partial pivoting and row interchanges is
used to factor A as
A = P * L * U,
where P is a permutation matrix, L is unit lower triangular, and U is
upper triangular. The factored form of A is then used to solve the
system of equations A * X = B.
Arguments
| N |
(input) INTEGER
The number of linear equations, i.e., the order of the
matrix A. N >= 0. |
| NRHS |
(input) INTEGER
The number of right hand sides, i.e., the number of columns
of the matrix B. NRHS >= 0. |
| A |
(input/output) COMPLEX*16 array, dimension (LDA,N)
On entry, the N-by-N coefficient matrix A.
On exit, the factors L and U from the factorization A = P*L*U; the unit diagonal elements of L are not stored. |
| LDA |
(input) INTEGER
The leading dimension of the array A. LDA >= max(1,N).
|
| IPIV |
(output) INTEGER array, dimension (N)
The pivot indices that define the permutation matrix P;
row i of the matrix was interchanged with row IPIV(i). |
| B |
(input/output) COMPLEX*16 array, dimension (LDB,NRHS)
On entry, the N-by-NRHS matrix of right hand side matrix B.
On exit, if INFO = 0, the N-by-NRHS solution matrix X. |
| LDB |
(input) INTEGER
The leading dimension of the array B. LDB >= max(1,N).
|
| 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 factorization has been completed, but the factor U is exactly singular, so the solution could not be computed. |