LAPACK 3.11.0
LAPACK: Linear Algebra PACKage

◆ dgsvts3()

subroutine dgsvts3 ( integer  M,
integer  P,
integer  N,
double precision, dimension( lda, * )  A,
double precision, dimension( lda, * )  AF,
integer  LDA,
double precision, dimension( ldb, * )  B,
double precision, dimension( ldb, * )  BF,
integer  LDB,
double precision, dimension( ldu, * )  U,
integer  LDU,
double precision, dimension( ldv, * )  V,
integer  LDV,
double precision, dimension( ldq, * )  Q,
integer  LDQ,
double precision, dimension( * )  ALPHA,
double precision, dimension( * )  BETA,
double precision, dimension( ldr, * )  R,
integer  LDR,
integer, dimension( * )  IWORK,
double precision, dimension( lwork )  WORK,
integer  LWORK,
double precision, dimension( * )  RWORK,
double precision, dimension( 6 )  RESULT 
)

DGSVTS3

Purpose:
 DGSVTS3 tests DGGSVD3, which computes the GSVD of an M-by-N matrix A
 and a P-by-N matrix B:
              U'*A*Q = D1*R and V'*B*Q = D2*R.
Parameters
[in]M
          M is INTEGER
          The number of rows of the matrix A.  M >= 0.
[in]P
          P is INTEGER
          The number of rows of the matrix B.  P >= 0.
[in]N
          N is INTEGER
          The number of columns of the matrices A and B.  N >= 0.
[in]A
          A is DOUBLE PRECISION array, dimension (LDA,M)
          The M-by-N matrix A.
[out]AF
          AF is DOUBLE PRECISION array, dimension (LDA,N)
          Details of the GSVD of A and B, as returned by DGGSVD3,
          see DGGSVD3 for further details.
[in]LDA
          LDA is INTEGER
          The leading dimension of the arrays A and AF.
          LDA >= max( 1,M ).
[in]B
          B is DOUBLE PRECISION array, dimension (LDB,P)
          On entry, the P-by-N matrix B.
[out]BF
          BF is DOUBLE PRECISION array, dimension (LDB,N)
          Details of the GSVD of A and B, as returned by DGGSVD3,
          see DGGSVD3 for further details.
[in]LDB
          LDB is INTEGER
          The leading dimension of the arrays B and BF.
          LDB >= max(1,P).
[out]U
          U is DOUBLE PRECISION array, dimension(LDU,M)
          The M by M orthogonal matrix U.
[in]LDU
          LDU is INTEGER
          The leading dimension of the array U. LDU >= max(1,M).
[out]V
          V is DOUBLE PRECISION array, dimension(LDV,M)
          The P by P orthogonal matrix V.
[in]LDV
          LDV is INTEGER
          The leading dimension of the array V. LDV >= max(1,P).
[out]Q
          Q is DOUBLE PRECISION array, dimension(LDQ,N)
          The N by N orthogonal matrix Q.
[in]LDQ
          LDQ is INTEGER
          The leading dimension of the array Q. LDQ >= max(1,N).
[out]ALPHA
          ALPHA is DOUBLE PRECISION array, dimension (N)
[out]BETA
          BETA is DOUBLE PRECISION array, dimension (N)

          The generalized singular value pairs of A and B, the
          ``diagonal'' matrices D1 and D2 are constructed from
          ALPHA and BETA, see subroutine DGGSVD3 for details.
[out]R
          R is DOUBLE PRECISION array, dimension(LDQ,N)
          The upper triangular matrix R.
[in]LDR
          LDR is INTEGER
          The leading dimension of the array R. LDR >= max(1,N).
[out]IWORK
          IWORK is INTEGER array, dimension (N)
[out]WORK
          WORK is DOUBLE PRECISION array, dimension (LWORK)
[in]LWORK
          LWORK is INTEGER
          The dimension of the array WORK,
          LWORK >= max(M,P,N)*max(M,P,N).
[out]RWORK
          RWORK is DOUBLE PRECISION array, dimension (max(M,P,N))
[out]RESULT
          RESULT is DOUBLE PRECISION array, dimension (6)
          The test ratios:
          RESULT(1) = norm( U'*A*Q - D1*R ) / ( MAX(M,N)*norm(A)*ULP)
          RESULT(2) = norm( V'*B*Q - D2*R ) / ( MAX(P,N)*norm(B)*ULP)
          RESULT(3) = norm( I - U'*U ) / ( M*ULP )
          RESULT(4) = norm( I - V'*V ) / ( P*ULP )
          RESULT(5) = norm( I - Q'*Q ) / ( N*ULP )
          RESULT(6) = 0        if ALPHA is in decreasing order;
                    = ULPINV   otherwise.
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.