LAPACK 3.11.0
LAPACK: Linear Algebra PACKage

◆ sbdt02()

subroutine sbdt02 ( integer  M,
integer  N,
real, dimension( ldb, * )  B,
integer  LDB,
real, dimension( ldc, * )  C,
integer  LDC,
real, dimension( ldu, * )  U,
integer  LDU,
real, dimension( * )  WORK,
real  RESID 
)

SBDT02

Purpose:
 SBDT02 tests the change of basis C = U**H * B by computing the
 residual

    RESID = norm(B - U * C) / ( max(m,n) * norm(B) * EPS ),

 where B and C are M by N matrices, U is an M by M orthogonal matrix,
 and EPS is the machine precision.
Parameters
[in]M
          M is INTEGER
          The number of rows of the matrices B and C and the order of
          the matrix Q.
[in]N
          N is INTEGER
          The number of columns of the matrices B and C.
[in]B
          B is REAL array, dimension (LDB,N)
          The m by n matrix B.
[in]LDB
          LDB is INTEGER
          The leading dimension of the array B.  LDB >= max(1,M).
[in]C
          C is REAL array, dimension (LDC,N)
          The m by n matrix C, assumed to contain U**H * B.
[in]LDC
          LDC is INTEGER
          The leading dimension of the array C.  LDC >= max(1,M).
[in]U
          U is REAL 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]WORK
          WORK is REAL array, dimension (M)
[out]RESID
          RESID is REAL
          RESID = norm(B - U * C) / ( max(m,n) * norm(B) * EPS ),
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.