ctrsv(3P) Sun Performance Library ctrsv(3P)NAMEctrsv - solve one of the systems of equations A*x = b, or A'*x = b,
or conjg( A' )*x = b
SYNOPSIS
SUBROUTINE CTRSV(UPLO, TRANSA, DIAG, N, A, LDA, Y, INCY)
CHARACTER * 1 UPLO, TRANSA, DIAG
COMPLEX A(LDA,*), Y(*)
INTEGER N, LDA, INCY
SUBROUTINE CTRSV_64(UPLO, TRANSA, DIAG, N, A, LDA, Y, INCY)
CHARACTER * 1 UPLO, TRANSA, DIAG
COMPLEX A(LDA,*), Y(*)
INTEGER*8 N, LDA, INCY
F95 INTERFACE
SUBROUTINE TRSV(UPLO, [TRANSA], DIAG, [N], A, [LDA], Y, [INCY])
CHARACTER(LEN=1) :: UPLO, TRANSA, DIAG
COMPLEX, DIMENSION(:) :: Y
COMPLEX, DIMENSION(:,:) :: A
INTEGER :: N, LDA, INCY
SUBROUTINE TRSV_64(UPLO, [TRANSA], DIAG, [N], A, [LDA], Y, [INCY])
CHARACTER(LEN=1) :: UPLO, TRANSA, DIAG
COMPLEX, DIMENSION(:) :: Y
COMPLEX, DIMENSION(:,:) :: A
INTEGER(8) :: N, LDA, INCY
C INTERFACE
#include <sunperf.h>
void ctrsv(char uplo, char transa, char diag, int n, complex *a, int
lda, complex *y, int incy);
void ctrsv_64(char uplo, char transa, char diag, long n, complex *a,
long lda, complex *y, long incy);
PURPOSEctrsv solves one of the systems of equations A*x = b, or A'*x = b, or
conjg( A' )*x = b where b and x are n element vectors and A is an n by
n unit, or non-unit, upper or lower triangular matrix.
No test for singularity or near-singularity is included in this rou‐
tine. Such tests must be performed before calling this routine.
ARGUMENTS
UPLO (input)
On entry, UPLO specifies whether the matrix is an upper or
lower triangular matrix as follows:
UPLO = 'U' or 'u' A is an upper triangular matrix.
UPLO = 'L' or 'l' A is a lower triangular matrix.
Unchanged on exit.
TRANSA (input)
On entry, TRANSA specifies the equations to be solved as fol‐
lows:
TRANSA = 'N' or 'n' A*x = b.
TRANSA = 'T' or 't' A'*x = b.
TRANSA = 'C' or 'c' conjg( A' )*x = b.
Unchanged on exit.
TRANSA is defaulted to 'N' for F95 INTERFACE.
DIAG (input)
On entry, DIAG specifies whether or not A is unit triangular
as follows:
DIAG = 'U' or 'u' A is assumed to be unit triangular.
DIAG = 'N' or 'n' A is not assumed to be unit triangular.
Unchanged on exit.
N (input)
On entry, N specifies the order of the matrix A. N >= 0.
Unchanged on exit.
A (input)
Before entry with UPLO = 'U' or 'u', the leading n by n
upper triangular part of the array A must contain the upper
triangular matrix and the strictly lower triangular part of A
is not referenced. Before entry with UPLO = 'L' or 'l', the
leading n by n lower triangular part of the array A must con‐
tain the lower triangular matrix and the strictly upper tri‐
angular part of A is not referenced. Note that when DIAG =
'U' or 'u', the diagonal elements of A are not referenced
either, but are assumed to be unity. Unchanged on exit.
LDA (input)
On entry, LDA specifies the first dimension of A as declared
in the calling (sub) program. LDA >= max( 1, n ). Unchanged
on exit.
Y (input/output)
( 1 + ( n - 1 )*abs( INCY ) ). Before entry, the incremented
array Y must contain the n element right-hand side vector b.
On exit, Y is overwritten with the solution vector x.
INCY (input)
On entry, INCY specifies the increment for the elements of Y.
INCY <> 0. Unchanged on exit.
6 Mar 2009 ctrsv(3P)