Contents
ztrsyl - solve the complex Sylvester matrix equation
SUBROUTINE ZTRSYL(TRANA, TRANB, ISGN, M, N, A, LDA, B, LDB, C, LDC,
SCALE, INFO)
CHARACTER * 1 TRANA, TRANB
DOUBLE COMPLEX A(LDA,*), B(LDB,*), C(LDC,*)
INTEGER ISGN, M, N, LDA, LDB, LDC, INFO
DOUBLE PRECISION SCALE
SUBROUTINE ZTRSYL_64(TRANA, TRANB, ISGN, M, N, A, LDA, B, LDB, C,
LDC, SCALE, INFO)
CHARACTER * 1 TRANA, TRANB
DOUBLE COMPLEX A(LDA,*), B(LDB,*), C(LDC,*)
INTEGER*8 ISGN, M, N, LDA, LDB, LDC, INFO
DOUBLE PRECISION SCALE
F95 INTERFACE
SUBROUTINE TRSYL(TRANA, TRANB, ISGN, [M], [N], A, [LDA], B, [LDB], C,
[LDC], SCALE, [INFO])
CHARACTER(LEN=1) :: TRANA, TRANB
COMPLEX(8), DIMENSION(:,:) :: A, B, C
INTEGER :: ISGN, M, N, LDA, LDB, LDC, INFO
REAL(8) :: SCALE
SUBROUTINE TRSYL_64(TRANA, TRANB, ISGN, [M], [N], A, [LDA], B, [LDB],
C, [LDC], SCALE, [INFO])
CHARACTER(LEN=1) :: TRANA, TRANB
COMPLEX(8), DIMENSION(:,:) :: A, B, C
INTEGER(8) :: ISGN, M, N, LDA, LDB, LDC, INFO
REAL(8) :: SCALE
C INTERFACE
#include <sunperf.h>
void ztrsyl(char trana, char tranb, int isgn, int m, int n,
doublecomplex *a, int lda, doublecomplex *b, int
ldb, doublecomplex *c, int ldc, double *scale, int
*info);
void ztrsyl_64(char trana, char tranb, long isgn, long m,
long n, doublecomplex *a, long lda, doublecomplex
*b, long ldb, doublecomplex *c, long ldc, double
*scale, long *info);
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 triangu-
lar. 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 fac-
tor, set <= 1 to avoid overflow in X.
TRANA (input)
Specifies the option op(A):
= 'N': op(A) = A (No transpose)
= 'C': op(A) = A**H (Conjugate transpose)
TRANB (input)
Specifies the option op(B):
= 'N': op(B) = B (No transpose)
= 'C': op(B) = B**H (Conjugate transpose)
ISGN (input)
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) 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 triangular matrix A.
LDA (input)
The leading dimension of the array A. LDA >=
max(1,M).
B (input) The upper triangular matrix B.
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 over-
flow in X.
INFO (output)
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an ille-
gal value
= 1: A and B have common or very close eigen-
values; perturbed values were used to solve the
equation (but the matrices A and B are unchanged).