SRC/ztrsyl.f(3)

NAME
SRC/ztrsyl.f

SYNOPSIS

  Functions/Subroutines
subroutine ztrsyl (trana, tranb, isgn, m, n, a, lda, b, ldb, c, ldc, scale, info)
ZTRSYL

Function/Subroutine Documentation

  subroutine ztrsyl (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, integer info)

ZTRSYL

Purpose:

     ZTRSYL 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.

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*16 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*16 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*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.

    LDC

              LDC is INTEGER
              The leading dimension of the array C. LDC >= max(1,M)

    SCALE

              SCALE is DOUBLE PRECISION
              The scale factor, scale, set <= 1 to avoid overflow in X.

    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).

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 155 of file ztrsyl.f.

Author

Generated automatically by Doxygen for LAPACK from the source code.