.TH "TESTING/EIG/zbdt05.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME TESTING/EIG/zbdt05.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBzbdt05\fP (m, n, a, lda, s, ns, u, ldu, vt, ldvt, work, resid)" .br .RI "\fBZBDT05\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine zbdt05 (integer m, integer n, complex*16, dimension( lda, * ) a, integer lda, double precision, dimension( * ) s, integer ns, complex*16, dimension( * ) u, integer ldu, complex*16, dimension( ldvt, * ) vt, integer ldvt, complex*16, dimension( * ) work, double precision resid)" .PP \fBZBDT05\fP .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> ZBDT05 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*16 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 DOUBLE PRECISION 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*16 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*16 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*16 array, dimension (M,N) !> .fi .PP .br \fIRESID\fP .PP .nf !> RESID is DOUBLE PRECISION !> 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 \fBzbdt05\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.