.TH "cgtcon.f" 3 "Wed Oct 15 2014" "Version 3.4.2" "LAPACK" \" -*- nroff -*-
.ad l
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.SH NAME
cgtcon.f \- 
.SH SYNOPSIS
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.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBcgtcon\fP (NORM, N, DL, D, DU, DU2, IPIV, ANORM, RCOND, WORK, INFO)"
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.RI "\fI\fBCGTCON\fP \fP"
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine cgtcon (characterNORM, integerN, complex, dimension( * )DL, complex, dimension( * )D, complex, dimension( * )DU, complex, dimension( * )DU2, integer, dimension( * )IPIV, realANORM, realRCOND, complex, dimension( * )WORK, integerINFO)"

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\fBCGTCON\fP  
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\fBPurpose: \fP
.RS 4

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.nf
 CGTCON estimates the reciprocal of the condition number of a complex
 tridiagonal matrix A using the LU factorization as computed by
 CGTTRF.

 An estimate is obtained for norm(inv(A)), and the reciprocal of the
 condition number is computed as RCOND = 1 / (ANORM * norm(inv(A))).
.fi
.PP
 
.RE
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\fBParameters:\fP
.RS 4
\fINORM\fP 
.PP
.nf
          NORM is CHARACTER*1
          Specifies whether the 1-norm condition number or the
          infinity-norm condition number is required:
          = '1' or 'O':  1-norm;
          = 'I':         Infinity-norm.
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.PP
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\fIN\fP 
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.nf
          N is INTEGER
          The order of the matrix A.  N >= 0.
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\fIDL\fP 
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          DL is COMPLEX array, dimension (N-1)
          The (n-1) multipliers that define the matrix L from the
          LU factorization of A as computed by CGTTRF.
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\fID\fP 
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.nf
          D is COMPLEX array, dimension (N)
          The n diagonal elements of the upper triangular matrix U from
          the LU factorization of A.
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\fIDU\fP 
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          DU is COMPLEX array, dimension (N-1)
          The (n-1) elements of the first superdiagonal of U.
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\fIDU2\fP 
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          DU2 is COMPLEX array, dimension (N-2)
          The (n-2) elements of the second superdiagonal of U.
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\fIIPIV\fP 
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.nf
          IPIV is INTEGER array, dimension (N)
          The pivot indices; for 1 <= i <= n, row i of the matrix was
          interchanged with row IPIV(i).  IPIV(i) will always be either
          i or i+1; IPIV(i) = i indicates a row interchange was not
          required.
.fi
.PP
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\fIANORM\fP 
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          ANORM is REAL
          If NORM = '1' or 'O', the 1-norm of the original matrix A.
          If NORM = 'I', the infinity-norm of the original matrix A.
.fi
.PP
.br
\fIRCOND\fP 
.PP
.nf
          RCOND is REAL
          The reciprocal of the condition number of the matrix A,
          computed as RCOND = 1/(ANORM * AINVNM), where AINVNM is an
          estimate of the 1-norm of inv(A) computed in this routine.
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.PP
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\fIWORK\fP 
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.nf
          WORK is COMPLEX array, dimension (2*N)
.fi
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\fIINFO\fP 
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.nf
          INFO is INTEGER
          = 0:  successful exit
          < 0:  if INFO = -i, the i-th argument had an illegal value
.fi
.PP
 
.RE
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\fBAuthor:\fP
.RS 4
Univ\&. of Tennessee 
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Univ\&. of California Berkeley 
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Univ\&. of Colorado Denver 
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NAG Ltd\&. 
.RE
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\fBDate:\fP
.RS 4
September 2012 
.RE
.PP

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Definition at line 141 of file cgtcon\&.f\&.
.SH "Author"
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Generated automatically by Doxygen for LAPACK from the source code\&.