.TH "SRC/slasd0.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME SRC/slasd0.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "subroutine \fBslasd0\fP (n, sqre, d, e, u, ldu, vt, ldvt, smlsiz, iwork, work, info)" .br .RI "\fBSLASD0\fP computes the singular values of a real upper bidiagonal n-by-m matrix B with diagonal d and off-diagonal e\&. Used by sbdsdc\&. " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "subroutine slasd0 (integer n, integer sqre, real, dimension( * ) d, real, dimension( * ) e, real, dimension( ldu, * ) u, integer ldu, real, dimension( ldvt, * ) vt, integer ldvt, integer smlsiz, integer, dimension( * ) iwork, real, dimension( * ) work, integer info)" .PP \fBSLASD0\fP computes the singular values of a real upper bidiagonal n-by-m matrix B with diagonal d and off-diagonal e\&. Used by sbdsdc\&. .PP \fBPurpose:\fP .RS 4 .PP .nf !> !> Using a divide and conquer approach, SLASD0 computes the singular !> value decomposition (SVD) of a real upper bidiagonal N-by-M !> matrix B with diagonal D and offdiagonal E, where M = N + SQRE\&. !> The algorithm computes orthogonal matrices U and VT such that !> B = U * S * VT\&. The singular values S are overwritten on D\&. !> !> A related subroutine, SLASDA, computes only the singular values, !> and optionally, the singular vectors in compact form\&. !> .fi .PP .RE .PP \fBParameters\fP .RS 4 \fIN\fP .PP .nf !> N is INTEGER !> On entry, the row dimension of the upper bidiagonal matrix\&. !> This is also the dimension of the main diagonal array D\&. !> .fi .PP .br \fISQRE\fP .PP .nf !> SQRE is INTEGER !> Specifies the column dimension of the bidiagonal matrix\&. !> = 0: The bidiagonal matrix has column dimension M = N; !> = 1: The bidiagonal matrix has column dimension M = N+1; !> .fi .PP .br \fID\fP .PP .nf !> D is REAL array, dimension (N) !> On entry D contains the main diagonal of the bidiagonal !> matrix\&. !> On exit D, if INFO = 0, contains its singular values\&. !> .fi .PP .br \fIE\fP .PP .nf !> E is REAL array, dimension (M-1) !> Contains the subdiagonal entries of the bidiagonal matrix\&. !> On exit, E has been destroyed\&. !> .fi .PP .br \fIU\fP .PP .nf !> U is REAL array, dimension (LDU, N) !> On exit, U contains the left singular vectors, !> if U passed in as (N, N) Identity\&. !> .fi .PP .br \fILDU\fP .PP .nf !> LDU is INTEGER !> On entry, leading dimension of U\&. !> .fi .PP .br \fIVT\fP .PP .nf !> VT is REAL array, dimension (LDVT, M) !> On exit, VT**T contains the right singular vectors, !> if VT passed in as (M, M) Identity\&. !> .fi .PP .br \fILDVT\fP .PP .nf !> LDVT is INTEGER !> On entry, leading dimension of VT\&. !> .fi .PP .br \fISMLSIZ\fP .PP .nf !> SMLSIZ is INTEGER !> On entry, maximum size of the subproblems at the !> bottom of the computation tree\&. !> .fi .PP .br \fIIWORK\fP .PP .nf !> IWORK is INTEGER array, dimension (8*N) !> .fi .PP .br \fIWORK\fP .PP .nf !> WORK is REAL array, dimension (3*M**2+2*M) !> .fi .PP .br \fIINFO\fP .PP .nf !> INFO is INTEGER !> = 0: successful exit\&. !> < 0: if INFO = -i, the i-th argument had an illegal value\&. !> > 0: if INFO = 1, a singular value did not converge !> .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 \fBContributors:\fP .RS 4 Ming Gu and Huan Ren, Computer Science Division, University of California at Berkeley, USA .RE .PP .PP Definition at line \fB150\fP of file \fBslasd0\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.