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 154 of file ctrsyl3.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0                SRC/ctrsyl3.f(3)