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## sla_gerpvgrw()

real function sla_gerpvgrw | ( | integer | n,
|  | integer | ncols,
|  | real, dimension( lda, * ) | a,
|  | integer | lda,
|  | real, dimension( ldaf, * ) | af,
|  | integer | ldaf )

SLA_GERPVGRW

Download SLA_GERPVGRW + dependencies [TGZ] [ZIP] [TXT]

Purpose:

      !>
      !> SLA_GERPVGRW computes the reciprocal pivot growth factor
      !> norm(A)/norm(U). The  norm is used. If this is
      !> much less than 1, the stability of the LU factorization of the
      !> (equilibrated) matrix A could be poor. This also means that the
      !> solution X, estimated condition numbers, and error bounds could be
      !> unreliable.
      !>

Parameters

  [in]

  N

      !>          N is INTEGER
      !>     The number of linear equations, i.e., the order of the
      !>     matrix A.  N >= 0.
      !>

  [in]

  NCOLS

      !>          NCOLS is INTEGER
      !>     The number of columns of the matrix A. NCOLS >= 0.
      !>

  [in]

  A

      !>          A is REAL array, dimension (LDA,N)
      !>     On entry, the N-by-N matrix A.
      !>

  [in]

  LDA

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

  [in]

  AF

      !>          AF is REAL array, dimension (LDAF,N)
      !>     The factors L and U from the factorization
      !>     A = P*L*U as computed by SGETRF.
      !>

  [in]

  LDAF

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

Author
  Univ. of Tennessee
  Univ. of California Berkeley
  Univ. of Colorado Denver
  NAG Ltd.