TESTING/EIG/sbdt05.f(3)    Library Functions Manual    TESTING/EIG/sbdt05.f(3)

NAME
       TESTING/EIG/sbdt05.f

SYNOPSIS
   Functions/Subroutines
       subroutine sbdt05 (m, n, a, lda, s, ns, u, ldu, vt, ldvt, work, resid)
           SBDT05

Function/Subroutine Documentation
   subroutine sbdt05 (integer m, integer n, real, dimension( lda, * ) a,
       integer lda, real, dimension( * ) s, integer ns, real, dimension( ldu,
       * ) u, integer ldu, real, dimension( ldvt, * ) vt, integer ldvt, real,
       dimension( * ) work, real resid)
       SBDT05

       Purpose:


           !>
           !> SBDT05 reconstructs a bidiagonal matrix B from its (partial) SVD:
           !>    S = U' * B * V
           !> where U and V are orthogonal matrices and S is diagonal.
           !>
           !> The test ratio to test the singular value decomposition is
           !>    RESID = norm( S - U' * B * V ) / ( n * norm(B) * EPS )
           !> where VT = V' and EPS is the machine precision.
           !>

       Parameters
           M

           !>          M is INTEGER
           !>          The number of rows of the matrices A and U.
           !>

           N

           !>          N is INTEGER
           !>          The number of columns of the matrices A and VT.
           !>

           A

           !>          A is REAL array, dimension (LDA,N)
           !>          The m by n matrix A.
           !>

           LDA

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

           S

           !>          S is REAL array, dimension (NS)
           !>          The singular values from the (partial) SVD of B, sorted in
           !>          decreasing order.
           !>

           NS

           !>          NS is INTEGER
           !>          The number of singular values/vectors from the (partial)
           !>          SVD of B.
           !>

           U

           !>          U is REAL array, dimension (LDU,NS)
           !>          The n by ns orthogonal matrix U in S = U' * B * V.
           !>

           LDU

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

           VT

           !>          VT is REAL array, dimension (LDVT,N)
           !>          The n by ns orthogonal matrix V in S = U' * B * V.
           !>

           LDVT

           !>          LDVT is INTEGER
           !>          The leading dimension of the array VT.
           !>

           WORK

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

           RESID

           !>          RESID is REAL
           !>          The test ratio:  norm(S - U' * A * V) / ( n * norm(A) * EPS )
           !>

       Author
           Univ. of Tennessee


           Univ. of California Berkeley


           Univ. of Colorado Denver


           NAG Ltd.

       Definition at line 125 of file sbdt05.f.

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

LAPACK                          Version 3.12.0         TESTING/EIG/sbdt05.f(3)