![]() |
LAPACK 3.12.0
LAPACK: Linear Algebra PACKage
|
| subroutine ztrsyl3 | ( | character | trana, |
| character | tranb, | ||
| integer | isgn, | ||
| integer | m, | ||
| integer | n, | ||
| complex*16, dimension( lda, * ) | a, | ||
| integer | lda, | ||
| complex*16, dimension( ldb, * ) | b, | ||
| integer | ldb, | ||
| complex*16, dimension( ldc, * ) | c, | ||
| integer | ldc, | ||
| double precision | scale, | ||
| double precision, dimension( ldswork, * ) | swork, | ||
| integer | ldswork, | ||
| integer | info ) |
ZTRSYL3
!> !> ZTRSYL3 solves the complex Sylvester matrix equation: !> !> op(A)*X + X*op(B) = scale*C or !> op(A)*X - X*op(B) = scale*C, !> !> where op(A) = A or A**H, and A and B are both upper triangular. A is !> M-by-M and B is N-by-N; the right hand side C and the solution X are !> M-by-N; and scale is an output scale factor, set <= 1 to avoid !> overflow in X. !> !> This is the block version of the algorithm. !>
| [in] | TRANA | !> TRANA is CHARACTER*1 !> Specifies the option op(A): !> = 'N': op(A) = A (No transpose) !> = 'C': op(A) = A**H (Conjugate transpose) !> |
| [in] | TRANB | !> TRANB is CHARACTER*1 !> Specifies the option op(B): !> = 'N': op(B) = B (No transpose) !> = 'C': op(B) = B**H (Conjugate transpose) !> |
| [in] | ISGN | !> ISGN is INTEGER !> Specifies the sign in the equation: !> = +1: solve op(A)*X + X*op(B) = scale*C !> = -1: solve op(A)*X - X*op(B) = scale*C !> |
| [in] | M | !> M is INTEGER !> The order of the matrix A, and the number of rows in the !> matrices X and C. M >= 0. !> |
| [in] | N | !> N is INTEGER !> The order of the matrix B, and the number of columns in the !> matrices X and C. N >= 0. !> |
| [in] | A | !> A is COMPLEX*16 array, dimension (LDA,M) !> The upper triangular matrix A. !> |
| [in] | LDA | !> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,M). !> |
| [in] | B | !> B is COMPLEX*16 array, dimension (LDB,N) !> The upper triangular matrix B. !> |
| [in] | LDB | !> LDB is INTEGER !> The leading dimension of the array B. LDB >= max(1,N). !> |
| [in,out] | C | !> C is COMPLEX*16 array, dimension (LDC,N) !> On entry, the M-by-N right hand side matrix C. !> On exit, C is overwritten by the solution matrix X. !> |
| [in] | LDC | !> LDC is INTEGER !> The leading dimension of the array C. LDC >= max(1,M) !> |
| [out] | SCALE | !> SCALE is DOUBLE PRECISION !> The scale factor, scale, set <= 1 to avoid overflow in X. !> |
| [out] | SWORK | !> SWORK is DOUBLE PRECISION array, dimension (MAX(2, ROWS), !> MAX(1,COLS)). !> On exit, if INFO = 0, SWORK(1) returns the optimal value ROWS !> and SWORK(2) returns the optimal COLS. !> |
| [in] | LDSWORK | !> LDSWORK is INTEGER !> LDSWORK >= MAX(2,ROWS), where ROWS = ((M + NB - 1) / NB + 1) !> and NB is the optimal block size. !> !> If LDSWORK = -1, then a workspace query is assumed; the routine !> only calculates the optimal dimensions of the SWORK matrix, !> returns these values as the first and second entry of the SWORK !> matrix, and no error message related LWORK is issued by XERBLA. !> |
| [out] | INFO | !> INFO is INTEGER !> = 0: successful exit !> < 0: if INFO = -i, the i-th argument had an illegal value !> = 1: A and B have common or very close eigenvalues; perturbed !> values were used to solve the equation (but the matrices !> A and B are unchanged). !> |