TESTING/EIG/sort01.f(3)    Library Functions Manual    TESTING/EIG/sort01.f(3)

NAME
       TESTING/EIG/sort01.f

SYNOPSIS
   Functions/Subroutines
       subroutine sort01 (rowcol, m, n, u, ldu, work, lwork, resid)
           SORT01

Function/Subroutine Documentation
   subroutine sort01 (character rowcol, integer m, integer n, real, dimension(
       ldu, * ) u, integer ldu, real, dimension( * ) work, integer lwork, real
       resid)
       SORT01

       Purpose:


           !>
           !> SORT01 checks that the matrix U is orthogonal by computing the ratio
           !>
           !>    RESID = norm( I - U*U' ) / ( n * EPS ), if ROWCOL = 'R',
           !> or
           !>    RESID = norm( I - U'*U ) / ( m * EPS ), if ROWCOL = 'C'.
           !>
           !> Alternatively, if there isn't sufficient workspace to form
           !> I - U*U' or I - U'*U, the ratio is computed as
           !>
           !>    RESID = abs( I - U*U' ) / ( n * EPS ), if ROWCOL = 'R',
           !> or
           !>    RESID = abs( I - U'*U ) / ( m * EPS ), if ROWCOL = 'C'.
           !>
           !> where EPS is the machine precision.  ROWCOL is used only if m = n;
           !> if m > n, ROWCOL is assumed to be 'C', and if m < n, ROWCOL is
           !> assumed to be 'R'.
           !>

       Parameters
           ROWCOL

           !>          ROWCOL is CHARACTER
           !>          Specifies whether the rows or columns of U should be checked
           !>          for orthogonality.  Used only if M = N.
           !>          = 'R':  Check for orthogonal rows of U
           !>          = 'C':  Check for orthogonal columns of U
           !>

           M

           !>          M is INTEGER
           !>          The number of rows of the matrix U.
           !>

           N

           !>          N is INTEGER
           !>          The number of columns of the matrix U.
           !>

           U

           !>          U is REAL array, dimension (LDU,N)
           !>          The orthogonal matrix U.  U is checked for orthogonal columns
           !>          if m > n or if m = n and ROWCOL = 'C'.  U is checked for
           !>          orthogonal rows if m < n or if m = n and ROWCOL = 'R'.
           !>

           LDU

           !>          LDU is INTEGER
           !>          The leading dimension of the array U.  LDU >= max(1,M).
           !>

           WORK

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

           LWORK

           !>          LWORK is INTEGER
           !>          The length of the array WORK.  For best performance, LWORK
           !>          should be at least N*(N+1) if ROWCOL = 'C' or M*(M+1) if
           !>          ROWCOL = 'R', but the test will be done even if LWORK is 0.
           !>

           RESID

           !>          RESID is REAL
           !>          RESID = norm( I - U * U' ) / ( n * EPS ), if ROWCOL = 'R', or
           !>          RESID = norm( I - U' * U ) / ( m * EPS ), if ROWCOL = 'C'.
           !>

       Author
           Univ. of Tennessee


           Univ. of California Berkeley


           Univ. of Colorado Denver


           NAG Ltd.

       Definition at line 115 of file sort01.f.

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

LAPACK                          Version 3.12.0         TESTING/EIG/sort01.f(3)