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SUBROUTINE <a name="ZGECON.1"></a><a href="zgecon.f.html#ZGECON.1">ZGECON</a>( NORM, N, A, LDA, ANORM, RCOND, WORK, RWORK,
$ INFO )
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> -- LAPACK routine (version 3.1) --
</span><span class="comment">*</span><span class="comment"> Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
</span><span class="comment">*</span><span class="comment"> November 2006
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Modified to call <a name="ZLACN2.8"></a><a href="zlacn2.f.html#ZLACN2.1">ZLACN2</a> in place of <a name="ZLACON.8"></a><a href="zlacon.f.html#ZLACON.1">ZLACON</a>, 10 Feb 03, SJH.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> .. Scalar Arguments ..
</span> CHARACTER NORM
INTEGER INFO, LDA, N
DOUBLE PRECISION ANORM, RCOND
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. Array Arguments ..
</span> DOUBLE PRECISION RWORK( * )
COMPLEX*16 A( LDA, * ), WORK( * )
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Purpose
</span><span class="comment">*</span><span class="comment"> =======
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> <a name="ZGECON.23"></a><a href="zgecon.f.html#ZGECON.1">ZGECON</a> estimates the reciprocal of the condition number of a general
</span><span class="comment">*</span><span class="comment"> complex matrix A, in either the 1-norm or the infinity-norm, using
</span><span class="comment">*</span><span class="comment"> the LU factorization computed by <a name="ZGETRF.25"></a><a href="zgetrf.f.html#ZGETRF.1">ZGETRF</a>.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> An estimate is obtained for norm(inv(A)), and the reciprocal of the
</span><span class="comment">*</span><span class="comment"> condition number is computed as
</span><span class="comment">*</span><span class="comment"> RCOND = 1 / ( norm(A) * norm(inv(A)) ).
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Arguments
</span><span class="comment">*</span><span class="comment"> =========
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> NORM (input) CHARACTER*1
</span><span class="comment">*</span><span class="comment"> Specifies whether the 1-norm condition number or the
</span><span class="comment">*</span><span class="comment"> infinity-norm condition number is required:
</span><span class="comment">*</span><span class="comment"> = '1' or 'O': 1-norm;
</span><span class="comment">*</span><span class="comment"> = 'I': Infinity-norm.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> N (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The order of the matrix A. N >= 0.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> A (input) COMPLEX*16 array, dimension (LDA,N)
</span><span class="comment">*</span><span class="comment"> The factors L and U from the factorization A = P*L*U
</span><span class="comment">*</span><span class="comment"> as computed by <a name="ZGETRF.45"></a><a href="zgetrf.f.html#ZGETRF.1">ZGETRF</a>.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> LDA (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The leading dimension of the array A. LDA >= max(1,N).
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> ANORM (input) DOUBLE PRECISION
</span><span class="comment">*</span><span class="comment"> If NORM = '1' or 'O', the 1-norm of the original matrix A.
</span><span class="comment">*</span><span class="comment"> If NORM = 'I', the infinity-norm of the original matrix A.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> RCOND (output) DOUBLE PRECISION
</span><span class="comment">*</span><span class="comment"> The reciprocal of the condition number of the matrix A,
</span><span class="comment">*</span><span class="comment"> computed as RCOND = 1/(norm(A) * norm(inv(A))).
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> WORK (workspace) COMPLEX*16 array, dimension (2*N)
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> RWORK (workspace) DOUBLE PRECISION array, dimension (2*N)
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> INFO (output) INTEGER
</span><span class="comment">*</span><span class="comment"> = 0: successful exit
</span><span class="comment">*</span><span class="comment"> < 0: if INFO = -i, the i-th argument had an illegal value
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> =====================================================================
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> .. Parameters ..
</span> DOUBLE PRECISION ONE, ZERO
PARAMETER ( ONE = 1.0D+0, ZERO = 0.0D+0 )
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. Local Scalars ..
</span> LOGICAL ONENRM
CHARACTER NORMIN
INTEGER IX, KASE, KASE1
DOUBLE PRECISION AINVNM, SCALE, SL, SMLNUM, SU
COMPLEX*16 ZDUM
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. Local Arrays ..
</span> INTEGER ISAVE( 3 )
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. External Functions ..
</span> LOGICAL <a name="LSAME.83"></a><a href="lsame.f.html#LSAME.1">LSAME</a>
INTEGER IZAMAX
DOUBLE PRECISION <a name="DLAMCH.85"></a><a href="dlamch.f.html#DLAMCH.1">DLAMCH</a>
EXTERNAL <a name="LSAME.86"></a><a href="lsame.f.html#LSAME.1">LSAME</a>, IZAMAX, <a name="DLAMCH.86"></a><a href="dlamch.f.html#DLAMCH.1">DLAMCH</a>
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. External Subroutines ..
</span> EXTERNAL <a name="XERBLA.89"></a><a href="xerbla.f.html#XERBLA.1">XERBLA</a>, <a name="ZDRSCL.89"></a><a href="zdrscl.f.html#ZDRSCL.1">ZDRSCL</a>, <a name="ZLACN2.89"></a><a href="zlacn2.f.html#ZLACN2.1">ZLACN2</a>, <a name="ZLATRS.89"></a><a href="zlatrs.f.html#ZLATRS.1">ZLATRS</a>
<span class="comment">*</span><span class="comment"> ..
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