ztpsv(l) [redhat man page]

ZTPSV(l)							   BLAS routine 							  ZTPSV(l)

NAME

       ZTPSV - solve one of the systems of equations   A*x = b, or A'*x = b, or conjg( A' )*x = b,

SYNOPSIS

       SUBROUTINE ZTPSV ( UPLO, TRANS, DIAG, N, AP, X, INCX )

	   INTEGER	INCX, N

	   CHARACTER*1	DIAG, TRANS, UPLO

	   COMPLEX*16	AP( * ), X( * )

PURPOSE

       ZTPSV  solves one of the systems of equations

       where b and x are n element vectors and A is an n by n unit, or non-unit, upper or lower triangular matrix, supplied in packed form.

       No test for singularity or near-singularity is included in this routine. Such tests must be performed before calling this routine.

PARAMETERS

       UPLO   - CHARACTER*1.
	      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.

       TRANS  - CHARACTER*1.
	      On entry, TRANS specifies the equations to be solved as follows:

	      TRANS = 'N' or 'n'   A*x = b.

	      TRANS = 'T' or 't'   A'*x = b.

	      TRANS = 'C' or 'c'   conjg( A' )*x = b.

	      Unchanged on exit.

       DIAG   - CHARACTER*1.
	      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      - INTEGER.
	      On entry, N specifies the order of the matrix A.	N must be at least zero.  Unchanged on exit.

       AP     - COMPLEX*16	 array of DIMENSION at least
	      (  (  n*( n + 1 ) )/2 ).	Before entry with  UPLO = 'U' or 'u', the array AP must contain the upper triangular matrix packed sequen-
	      tially, column by column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 1, 2 ) and a( 2, 2 ) respectively,  and
	      so  on.	Before	entry with UPLO = 'L' or 'l', the array AP must contain the lower triangular matrix packed sequentially, column by
	      column, so that AP( 1 ) contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 2, 1 ) and a( 3, 1 ) respectively, and so on.	Note  that
	      when  DIAG = 'U' or 'u', the diagonal elements of A are not referenced, but are assumed to be unity.  Unchanged on exit.

       X      - COMPLEX*16	 array of dimension at least
	      (  1 + ( n - 1 )*abs( INCX ) ).  Before entry, the incremented array X must contain the n element right-hand side vector b. On exit,
	      X is overwritten with the solution vector x.

       INCX   - INTEGER.
	      On entry, INCX specifies the increment for the elements of X. INCX must not be zero.  Unchanged on exit.

	      Level 2 Blas routine.

	      -- Written on 22-October-1986.  Jack Dongarra, Argonne National Lab.  Jeremy Du Croz, Nag Central Office.  Sven Hammarling, Nag Cen-
	      tral Office.  Richard Hanson, Sandia National Labs.

BLAS routine							  16 October 1992							  ZTPSV(l)