.TH "slarra.f" 3 "Sun May 26 2013" "Version 3.4.1" "LAPACK" \" -*- nroff -*-
.ad l
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.SH NAME
slarra.f \- 
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBslarra\fP (N, D, E, E2, SPLTOL, TNRM, NSPLIT, ISPLIT, INFO)"
.br
.RI "\fI\fBSLARRA\fP \fP"
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine slarra (integerN, real, dimension( * )D, real, dimension( * )E, real, dimension( * )E2, realSPLTOL, realTNRM, integerNSPLIT, integer, dimension( * )ISPLIT, integerINFO)"

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

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.nf
 Compute the splitting points with threshold SPLTOL.
 SLARRA sets any "small" off-diagonal elements to zero.
.fi
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.RE
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\fBParameters:\fP
.RS 4
\fIN\fP 
.PP
.nf
          N is INTEGER
          The order of the matrix. N > 0.
.fi
.PP
.br
\fID\fP 
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.nf
          D is REAL array, dimension (N)
          On entry, the N diagonal elements of the tridiagonal
          matrix T.
.fi
.PP
.br
\fIE\fP 
.PP
.nf
          E is REAL array, dimension (N)
          On entry, the first (N-1) entries contain the subdiagonal
          elements of the tridiagonal matrix T; E(N) need not be set.
          On exit, the entries E( ISPLIT( I ) ), 1 <= I <= NSPLIT,
          are set to zero, the other entries of E are untouched.
.fi
.PP
.br
\fIE2\fP 
.PP
.nf
          E2 is REAL array, dimension (N)
          On entry, the first (N-1) entries contain the SQUARES of the
          subdiagonal elements of the tridiagonal matrix T;
          E2(N) need not be set.
          On exit, the entries E2( ISPLIT( I ) ),
          1 <= I <= NSPLIT, have been set to zero
.fi
.PP
.br
\fISPLTOL\fP 
.PP
.nf
          SPLTOL is REAL
          The threshold for splitting. Two criteria can be used:
          SPLTOL<0 : criterion based on absolute off-diagonal value
          SPLTOL>0 : criterion that preserves relative accuracy
.fi
.PP
.br
\fITNRM\fP 
.PP
.nf
          TNRM is REAL
          The norm of the matrix.
.fi
.PP
.br
\fINSPLIT\fP 
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.nf
          NSPLIT is INTEGER
          The number of blocks T splits into. 1 <= NSPLIT <= N.
.fi
.PP
.br
\fIISPLIT\fP 
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.nf
          ISPLIT is INTEGER array, dimension (N)
          The splitting points, at which T breaks up into blocks.
          The first block consists of rows/columns 1 to ISPLIT(1),
          the second of rows/columns ISPLIT(1)+1 through ISPLIT(2),
          etc., and the NSPLIT-th consists of rows/columns
          ISPLIT(NSPLIT-1)+1 through ISPLIT(NSPLIT)=N.
.fi
.PP
.br
\fIINFO\fP 
.PP
.nf
          INFO is INTEGER
          = 0:  successful exit
.fi
.PP
 
.RE
.PP
\fBAuthor:\fP
.RS 4
Univ\&. of Tennessee 
.PP
Univ\&. of California Berkeley 
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Univ\&. of Colorado Denver 
.PP
NAG Ltd\&. 
.RE
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\fBDate:\fP
.RS 4
November 2011 
.RE
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\fBContributors: \fP
.RS 4
Beresford Parlett, University of California, Berkeley, USA 
.br
 Jim Demmel, University of California, Berkeley, USA 
.br
 Inderjit Dhillon, University of Texas, Austin, USA 
.br
 Osni Marques, LBNL/NERSC, USA 
.br
 Christof Voemel, University of California, Berkeley, USA 
.RE
.PP

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Definition at line 136 of file slarra\&.f\&.
.SH "Author"
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Generated automatically by Doxygen for LAPACK from the source code\&.