Provided by: liblapack-doc_3.3.1-1_all bug

NAME

       LAPACK-3 - solves the complex Sylvester matrix equation

SYNOPSIS

       SUBROUTINE ZTRSYL( TRANA, TRANB, ISGN, M, N, A, LDA, B, LDB, C, LDC, SCALE, INFO )

           CHARACTER      TRANA, TRANB

           INTEGER        INFO, ISGN, LDA, LDB, LDC, M, N

           DOUBLE         PRECISION SCALE

           COMPLEX*16     A( LDA, * ), B( LDB, * ), C( LDC, * )

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.

ARGUMENTS

        TRANA   (input) CHARACTER*1
                Specifies the option op(A):
                = 'N': op(A) = A    (No transpose)
                = 'C': op(A) = A**H (Conjugate transpose)

        TRANB   (input) CHARACTER*1
                Specifies the option op(B):
                = 'N': op(B) = B    (No transpose)
                = 'C': op(B) = B**H (Conjugate transpose)

        ISGN    (input) 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       (input) INTEGER
                The order of the matrix A, and the number of rows in the
                matrices X and C. M >= 0.

        N       (input) INTEGER
                The order of the matrix B, and the number of columns in the
                matrices X and C. N >= 0.

        A       (input) COMPLEX*16 array, dimension (LDA,M)
                The upper triangular matrix A.

        LDA     (input) INTEGER
                The leading dimension of the array A. LDA >= max(1,M).

        B       (input) COMPLEX*16 array, dimension (LDB,N)
                The upper triangular matrix B.

        LDB     (input) INTEGER
                The leading dimension of the array B. LDB >= max(1,N).

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

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

        INFO    (output) 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).

 LAPACK routine (version 3.3.1)             April 2011                            ZTRSYL(3lapack)