STPSV(1)

NAME
LAPACK-3 - solves one of the systems of equations A*x = b, or A**T*x = b,

SYNOPSIS

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

INTEGER
    INCX,N

CHARACTER
    DIAG,TRANS,UPLO

REAL
    AP(*),X(*)

PURPOSE
STPSV 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.

ARGUMENTS

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**T*x = b.
     TRANS = 'C' or 'c' A**T*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     - REAL             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 sequentially,
     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      - REAL             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.

FURTHER DETAILS
 Level 2 Blas routine.
 -- Written on 22-October-1986.
    Jack Dongarra, Argonne National Lab.
    Jeremy Du Croz, Nag Central Office.
    Sven Hammarling, Nag Central Office.
    Richard Hanson, Sandia National Labs.