TESTING/EIG/dort03.f(3)    Library Functions Manual    TESTING/EIG/dort03.f(3)

NAME
       TESTING/EIG/dort03.f

SYNOPSIS
   Functions/Subroutines
       subroutine dort03 (rc, mu, mv, n, k, u, ldu, v, ldv, work, lwork,
           result, info)
           DORT03

Function/Subroutine Documentation
   subroutine dort03 (character*( * ) rc, integer mu, integer mv, integer n,
       integer k, double precision, dimension( ldu, * ) u, integer ldu, double
       precision, dimension( ldv, * ) v, integer ldv, double precision,
       dimension( * ) work, integer lwork, double precision result, integer
       info)
       DORT03

       Purpose:


            DORT03 compares two orthogonal matrices U and V to see if their
            corresponding rows or columns span the same spaces.  The rows are
            checked if RC = 'R', and the columns are checked if RC = 'C'.

            RESULT is the maximum of

               | V*V' - I | / ( MV ulp ), if RC = 'R', or

               | V'*V - I | / ( MV ulp ), if RC = 'C',

            and the maximum over rows (or columns) 1 to K of

               | U(i) - S*V(i) |/ ( N ulp )

            where S is +-1 (chosen to minimize the expression), U(i) is the i-th
            row (column) of U, and V(i) is the i-th row (column) of V.

       Parameters
           RC

                     RC is CHARACTER*1
                     If RC = 'R' the rows of U and V are to be compared.
                     If RC = 'C' the columns of U and V are to be compared.

           MU

                     MU is INTEGER
                     The number of rows of U if RC = 'R', and the number of
                     columns if RC = 'C'.  If MU = 0 DORT03 does nothing.
                     MU must be at least zero.

           MV

                     MV is INTEGER
                     The number of rows of V if RC = 'R', and the number of
                     columns if RC = 'C'.  If MV = 0 DORT03 does nothing.
                     MV must be at least zero.

           N

                     N is INTEGER
                     If RC = 'R', the number of columns in the matrices U and V,
                     and if RC = 'C', the number of rows in U and V.  If N = 0
                     DORT03 does nothing.  N must be at least zero.

           K

                     K is INTEGER
                     The number of rows or columns of U and V to compare.
                     0 <= K <= max(MU,MV).

           U

                     U is DOUBLE PRECISION array, dimension (LDU,N)
                     The first matrix to compare.  If RC = 'R', U is MU by N, and
                     if RC = 'C', U is N by MU.

           LDU

                     LDU is INTEGER
                     The leading dimension of U.  If RC = 'R', LDU >= max(1,MU),
                     and if RC = 'C', LDU >= max(1,N).

           V

                     V is DOUBLE PRECISION array, dimension (LDV,N)
                     The second matrix to compare.  If RC = 'R', V is MV by N, and
                     if RC = 'C', V is N by MV.

           LDV

                     LDV is INTEGER
                     The leading dimension of V.  If RC = 'R', LDV >= max(1,MV),
                     and if RC = 'C', LDV >= max(1,N).

           WORK

                     WORK is DOUBLE PRECISION array, dimension (LWORK)

           LWORK

                     LWORK is INTEGER
                     The length of the array WORK.  For best performance, LWORK
                     should be at least N*N if RC = 'C' or M*M if RC = 'R', but
                     the tests will be done even if LWORK is 0.

           RESULT

                     RESULT is DOUBLE PRECISION
                     The value computed by the test described above.  RESULT is
                     limited to 1/ulp to avoid overflow.

           INFO

                     INFO is INTEGER
                     0  indicates a successful exit
                     -k indicates the k-th parameter had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 154 of file dort03.f.

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

LAPACK                          Version 3.12.0         TESTING/EIG/dort03.f(3)