SRC/ctrsyl3.f(3) Library Functions Manual SRC/ctrsyl3.f(3) NAME SRC/ctrsyl3.f SYNOPSIS Functions/Subroutines subroutine ctrsyl3 (trana, tranb, isgn, m, n, a, lda, b, ldb, c, ldc, scale, swork, ldswork, info) CTRSYL3 Function/Subroutine Documentation subroutine ctrsyl3 (character trana, character tranb, integer isgn, integer m, integer n, complex, dimension( lda, * ) a, integer lda, complex, dimension( ldb, * ) b, integer ldb, complex, dimension( ldc, * ) c, integer ldc, real scale, real, dimension( ldswork, * ) swork, integer ldswork, integer info) CTRSYL3 Purpose: !> !> CTRSYL3 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. !> Parameters TRANA !> TRANA is CHARACTER*1 !> Specifies the option op(A): !> = 'N': op(A) = A (No transpose) !> = 'C': op(A) = A**H (Conjugate transpose) !> TRANB !> TRANB is CHARACTER*1 !> Specifies the option op(B): !> = 'N': op(B) = B (No transpose) !> = 'C': op(B) = B**H (Conjugate transpose) !> 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 !> M !> M is INTEGER !> The order of the matrix A, and the number of rows in the !> matrices X and C. M >= 0. !> N !> N is INTEGER !> The order of the matrix B, and the number of columns in the !> matrices X and C. N >= 0. !> A !> A is COMPLEX array, dimension (LDA,M) !> The upper triangular matrix A. !> LDA !> LDA is INTEGER !> The leading dimension of the array A. LDA >= max(1,M). !> B !> B is COMPLEX array, dimension (LDB,N) !> The upper triangular matrix B. !> LDB !> LDB is INTEGER !> The leading dimension of the array B. LDB >= max(1,N). !> C !> C is COMPLEX 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. !> LDC !> LDC is INTEGER !> The leading dimension of the array C. LDC >= max(1,M) !> SCALE !> SCALE is REAL !> The scale factor, scale, set <= 1 to avoid overflow in X. !> SWORK !> SWORK is REAL 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. !> 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. !> 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). !> Definition at line 167 of file ctrsyl3.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 SRC/ctrsyl3.f(3)