.TH "TESTING/EIG/dsvdct.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
TESTING/EIG/dsvdct.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBdsvdct\fP (n, s, e, shift, num)"
.br
.RI "\fBDSVDCT\fP "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine dsvdct (integer n, double precision, dimension( * ) s, double precision, dimension( * ) e, double precision shift, integer num)"

.PP
\fBDSVDCT\fP 
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
 DSVDCT counts the number NUM of eigenvalues of a 2*N by 2*N
 tridiagonal matrix T which are less than or equal to SHIFT\&.  T is
 formed by putting zeros on the diagonal and making the off-diagonals
 equal to S(1), E(1), S(2), E(2), \&.\&.\&. , E(N-1), S(N)\&.  If SHIFT is
 positive, NUM is equal to N plus the number of singular values of a
 bidiagonal matrix B less than or equal to SHIFT\&.  Here B has diagonal
 entries S(1), \&.\&.\&., S(N) and superdiagonal entries E(1), \&.\&.\&. E(N-1)\&.
 If SHIFT is negative, NUM is equal to the number of singular values
 of B greater than or equal to -SHIFT\&.

 See W\&. Kahan 'Accurate Eigenvalues of a Symmetric Tridiagonal
 Matrix', Report CS41, Computer Science Dept\&., Stanford University,
 July 21, 1966
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fIN\fP 
.PP
.nf
          N is INTEGER
          The dimension of the bidiagonal matrix B\&.
.fi
.PP
.br
\fIS\fP 
.PP
.nf
          S is DOUBLE PRECISION array, dimension (N)
          The diagonal entries of the bidiagonal matrix B\&.
.fi
.PP
.br
\fIE\fP 
.PP
.nf
          E is DOUBLE PRECISION array of dimension (N-1)
          The superdiagonal entries of the bidiagonal matrix B\&.
.fi
.PP
.br
\fISHIFT\fP 
.PP
.nf
          SHIFT is DOUBLE PRECISION
          The shift, used as described under Purpose\&.
.fi
.PP
.br
\fINUM\fP 
.PP
.nf
          NUM is INTEGER
          The number of eigenvalues of T less than or equal to SHIFT\&.
.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 \fB86\fP of file \fBdsvdct\&.f\fP\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.