NAME

SYNOPSIS

  SUBROUTINE DTRSYL( TRANA, TRANB, ISGN, M, N, A, LDA, B, LDB, C, LDC, 
 *      SCALE, INFO)
  CHARACTER * 1 TRANA, TRANB
  INTEGER ISGN, M, N, LDA, LDB, LDC, INFO
  DOUBLE PRECISION SCALE
  DOUBLE PRECISION A(LDA,*), B(LDB,*), C(LDC,*)
 
  SUBROUTINE DTRSYL_64( TRANA, TRANB, ISGN, M, N, A, LDA, B, LDB, C, 
 *      LDC, SCALE, INFO)
  CHARACTER * 1 TRANA, TRANB
  INTEGER*8 ISGN, M, N, LDA, LDB, LDC, INFO
  DOUBLE PRECISION SCALE
  DOUBLE PRECISION A(LDA,*), B(LDB,*), C(LDC,*)
 

F95 INTERFACE

  SUBROUTINE TRSYL( TRANA, TRANB, ISGN, M, N, A, [LDA], B, [LDB], C, 
 *       [LDC], SCALE, [INFO])
  CHARACTER(LEN=1) :: TRANA, TRANB
  INTEGER :: ISGN, M, N, LDA, LDB, LDC, INFO
  REAL(8) :: SCALE
  REAL(8), DIMENSION(:,:) :: A, B, C
 
  SUBROUTINE TRSYL_64( TRANA, TRANB, ISGN, M, N, A, [LDA], B, [LDB], 
 *       C, [LDC], SCALE, [INFO])
  CHARACTER(LEN=1) :: TRANA, TRANB
  INTEGER(8) :: ISGN, M, N, LDA, LDB, LDC, INFO
  REAL(8) :: SCALE
  REAL(8), DIMENSION(:,:) :: A, B, C
 

C INTERFACE

void dtrsyl(char trana, char tranb, int isgn, int m, int n, double *a, int lda, double *b, int ldb, double *c, int ldc, double *scale, int *info);

void dtrsyl_64(char trana, char tranb, long isgn, long m, long n, double *a, long lda, double *b, long ldb, double *c, long ldc, double *scale, long *info);

PURPOSE

   op(A)*X + X*op(B) = scale*C or
   op(A)*X - X*op(B) = scale*C,

where op(A) = A or A**T, and A and B are both upper quasi- 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.

A and B must be in Schur canonical form (as returned by SHSEQR), that is, block upper triangular with 1-by-1 and 2-by-2 diagonal blocks; each 2-by-2 diagonal block has its diagonal elements equal and its off-diagonal elements of opposite sign.

ARGUMENTS

* TRANA (input)

Specifies the option op(A):

* TRANB (input)

Specifies the option op(B):

* ISGN (input)

Specifies the sign in the equation:

* M (input)

The order of the matrix A, and the number of rows in the matrices X and C. M >= 0.

* N (input)

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

* A (input)

The upper quasi-triangular matrix A, in Schur canonical form.

* LDA (input)

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

* B (input)

The upper quasi-triangular matrix B, in Schur canonical form.

* LDB (input)

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

* C (input/output)

On entry, the M-by-N right hand side matrix C. On exit, C is overwritten by the solution matrix X.

* LDC (input)

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

* SCALE (output)

The scale factor, scale, set <= 1 to avoid overflow in X.

* INFO (output)