.TH "TESTING/EIG/cbdt05.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME TESTING/EIG/cbdt05.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBcbdt05\fP (m, n, a, lda, s, ns, u, ldu, vt, ldvt, work, resid)" .br .RI "\fBCBDT05\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "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)" .PP \fBCBDT05\fP .PP \fBPurpose:\fP .RS 4 .PP .nf 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\&. .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIM\fP .PP .nf M is INTEGER The number of rows of the matrices A and U\&. .fi .PP .br \fIN\fP .PP .nf N is INTEGER The number of columns of the matrices A and VT\&. .fi .PP .br \fIA\fP .PP .nf A is COMPLEX array, dimension (LDA,N) The m by n matrix A\&. .fi .PP .br \fILDA\fP .PP .nf LDA is INTEGER The leading dimension of the array A\&. LDA >= max(1,M)\&. .fi .PP .br \fIS\fP .PP .nf S is REAL array, dimension (NS) The singular values from the (partial) SVD of B, sorted in decreasing order\&. .fi .PP .br \fINS\fP .PP .nf NS is INTEGER The number of singular values/vectors from the (partial) SVD of B\&. .fi .PP .br \fIU\fP .PP .nf U is COMPLEX array, dimension (LDU,NS) The n by ns orthogonal matrix U in S = U' * B * V\&. .fi .PP .br \fILDU\fP .PP .nf LDU is INTEGER The leading dimension of the array U\&. LDU >= max(1,N) .fi .PP .br \fIVT\fP .PP .nf VT is COMPLEX array, dimension (LDVT,N) The n by ns orthogonal matrix V in S = U' * B * V\&. .fi .PP .br \fILDVT\fP .PP .nf LDVT is INTEGER The leading dimension of the array VT\&. .fi .PP .br \fIWORK\fP .PP .nf WORK is COMPLEX array, dimension (M,N) .fi .PP .br \fIRESID\fP .PP .nf RESID is REAL The test ratio: norm(S - U' * A * V) / ( n * norm(A) * EPS ) .fi .PP .RE .PP \fBAuthor\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP .PP Definition at line \fB123\fP of file \fBcbdt05\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.