Contents
cstsv - compute the solution to a complex system of linear
equations A * X = B where A is a symmetric tridiagonal
matrix
SUBROUTINE CSTSV(N, NRHS, L, D, SUBL, B, LDB, IPIV, INFO)
COMPLEX L(*), D(*), SUBL(*), B(LDB,*)
INTEGER N, NRHS, LDB, INFO
INTEGER IPIV(*)
SUBROUTINE CSTSV_64(N, NRHS, L, D, SUBL, B, LDB, IPIV, INFO)
COMPLEX L(*), D(*), SUBL(*), B(LDB,*)
INTEGER*8 N, NRHS, LDB, INFO
INTEGER*8 IPIV(*)
F95 INTERFACE
SUBROUTINE STSV([N], [NRHS], L, D, SUBL, B, [LDB], IPIV, [INFO])
COMPLEX, DIMENSION(:) :: L, D, SUBL
COMPLEX, DIMENSION(:,:) :: B
INTEGER :: N, NRHS, LDB, INFO
INTEGER, DIMENSION(:) :: IPIV
SUBROUTINE STSV_64([N], [NRHS], L, D, SUBL, B, [LDB], IPIV, [INFO])
COMPLEX, DIMENSION(:) :: L, D, SUBL
COMPLEX, DIMENSION(:,:) :: B
INTEGER(8) :: N, NRHS, LDB, INFO
INTEGER(8), DIMENSION(:) :: IPIV
C INTERFACE
#include <sunperf.h>
void cstsv(int n, int nrhs, complex *l, complex *d, complex
*subl, complex *b, int ldb, int *ipiv, int *info);
void cstsv_64(long n, long nrhs, complex *l, complex *d,
complex *subl, complex *b, long ldb, long *ipiv,
long *info);
cstsv computes the solution to a complex system of linear
equations A * X = B where A is a symmetric tridiagonal
matrix.
N (input)
The order of the matrix A. N >= 0.
NRHS (input)
The number of right hand sides in B.
L (input/output)
COMPLEX array, dimension (N-1)
On entry, the n-1 subdiagonal elements of the tri-
diagonal matrix A. On exit, part of the factori-
zation of A.
D (input/output)
REAL array, dimension (N)
On entry, the n diagonal elements of the tridiago-
nal matrix A. On exit, the n diagonal elements of
the diagonal matrix D from the factorization of A.
SUBL (output)
COMPLEX array, dimension (N-2)
On exit, part of the factorization of A.
B (input/output)
The columns of B contain the right hand sides.
LDB (input)
The leading dimension of B as specified in a type
or DIMENSION statement.
IPIV (output)
INTEGER array, dimension (N)
On exit, the pivot indices of the factorization.
INFO (output)
INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an ille-
gal value
> 0: if INFO = i, D(k,k) is exactly zero. The
factorization has been completed, but the block
diagonal matrix D is exactly singular and division
by zero will occur if it is used to solve a system
of equations.