TESTING/EIG/cbdt05.f(3) Library Functions Manual TESTING/EIG/cbdt05.f(3) NAME TESTING/EIG/cbdt05.f SYNOPSIS Functions/Subroutines subroutine cbdt05 (m, n, a, lda, s, ns, u, ldu, vt, ldvt, work, resid) CBDT05 Function/Subroutine Documentation subroutine cbdt05 (integer m, integer n, complex, dimension( lda, * ) a, integer lda, real, dimension( * ) s, integer ns, complex, dimension( * ) u, integer ldu, complex, dimension( ldvt, * ) vt, integer ldvt, complex, dimension( * ) work, real resid) CBDT05 Purpose: !> !> CBDT05 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 COMPLEX 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 COMPLEX 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 COMPLEX 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 COMPLEX 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 123 of file cbdt05.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 TESTING/EIG/cbdt05.f(3)