TESTING/LIN/stpt02.f(3)    Library Functions Manual    TESTING/LIN/stpt02.f(3)

NAME
       TESTING/LIN/stpt02.f

SYNOPSIS
   Functions/Subroutines
       subroutine stpt02 (uplo, trans, diag, n, nrhs, ap, x, ldx, b, ldb,
           work, resid)
           STPT02

Function/Subroutine Documentation
   subroutine stpt02 (character uplo, character trans, character diag, integer
       n, integer nrhs, real, dimension( * ) ap, real, dimension( ldx, * ) x,
       integer ldx, real, dimension( ldb, * ) b, integer ldb, real, dimension(
       * ) work, real resid)
       STPT02

       Purpose:


           !>
           !> STPT02 computes the residual for the computed solution to a
           !> triangular system of linear equations op(A)*X = B, when the
           !> triangular matrix A is stored in packed format. The test ratio is
           !> the maximum over
           !>    norm(b - op(A)*x) / ( ||op(A)||_1 * norm(x) * EPS ),
           !> where op(A) = A or A**T, b is the column of B, x is the solution
           !> vector, and EPS is the machine epsilon.
           !> The norm used is the 1-norm.
           !>

       Parameters
           UPLO

           !>          UPLO is CHARACTER*1
           !>          Specifies whether the matrix A is upper or lower triangular.
           !>          = 'U':  Upper triangular
           !>          = 'L':  Lower triangular
           !>

           TRANS

           !>          TRANS is CHARACTER*1
           !>          Specifies the operation applied to A.
           !>          = 'N':  A    * X = B  (No transpose)
           !>          = 'T':  A**T * X = B  (Transpose)
           !>          = 'C':  A**H * X = B  (Conjugate transpose = Transpose)
           !>

           DIAG

           !>          DIAG is CHARACTER*1
           !>          Specifies whether or not the matrix A is unit triangular.
           !>          = 'N':  Non-unit triangular
           !>          = 'U':  Unit triangular
           !>

           N

           !>          N is INTEGER
           !>          The order of the matrix A.  N >= 0.
           !>

           NRHS

           !>          NRHS is INTEGER
           !>          The number of right hand sides, i.e., the number of columns
           !>          of the matrices X and B.  NRHS >= 0.
           !>

           AP

           !>          AP is REAL array, dimension (N*(N+1)/2)
           !>          The upper or lower triangular matrix A, packed columnwise in
           !>          a linear array.  The j-th column of A is stored in the array
           !>          AP as follows:
           !>          if UPLO = 'U', AP((j-1)*j/2 + i) = A(i,j) for 1<=i<=j;
           !>          if UPLO = 'L',
           !>             AP((j-1)*(n-j) + j*(j+1)/2 + i-j) = A(i,j) for j<=i<=n.
           !>

           X

           !>          X is REAL array, dimension (LDX,NRHS)
           !>          The computed solution vectors for the system of linear
           !>          equations.
           !>

           LDX

           !>          LDX is INTEGER
           !>          The leading dimension of the array X.  LDX >= max(1,N).
           !>

           B

           !>          B is REAL array, dimension (LDB,NRHS)
           !>          The right hand side vectors for the system of linear
           !>          equations.
           !>

           LDB

           !>          LDB is INTEGER
           !>          The leading dimension of the array B.  LDB >= max(1,N).
           !>

           WORK

           !>          WORK is REAL array, dimension (N)
           !>

           RESID

           !>          RESID is REAL
           !>          The maximum over the number of right hand sides of
           !>          norm(op(A)*X - B) / ( norm(op(A)) * norm(X) * EPS ).
           !>

       Author
           Univ. of Tennessee


           Univ. of California Berkeley


           Univ. of Colorado Denver


           NAG Ltd.

       Definition at line 140 of file stpt02.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0         TESTING/LIN/stpt02.f(3)