.TH "SRC/clacn2.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
SRC/clacn2.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBclacn2\fP (n, v, x, est, kase, isave)"
.br
.RI "\fBCLACN2\fP estimates the 1-norm of a square matrix, using reverse communication for evaluating matrix-vector products\&. "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine clacn2 (integer n, complex, dimension( * ) v, complex, dimension( * ) x, real est, integer kase, integer, dimension( 3 ) isave)"

.PP
\fBCLACN2\fP estimates the 1-norm of a square matrix, using reverse communication for evaluating matrix-vector products\&.  
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
 CLACN2 estimates the 1-norm of a square, complex matrix A\&.
 Reverse communication is used for evaluating matrix-vector products\&.
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fIN\fP 
.PP
.nf
          N is INTEGER
         The order of the matrix\&.  N >= 1\&.
.fi
.PP
.br
\fIV\fP 
.PP
.nf
          V is COMPLEX array, dimension (N)
         On the final return, V = A*W,  where  EST = norm(V)/norm(W)
         (W is not returned)\&.
.fi
.PP
.br
\fIX\fP 
.PP
.nf
          X is COMPLEX array, dimension (N)
         On an intermediate return, X should be overwritten by
               A * X,   if KASE=1,
               A**H * X,  if KASE=2,
         where A**H is the conjugate transpose of A, and CLACN2 must be
         re-called with all the other parameters unchanged\&.
.fi
.PP
.br
\fIEST\fP 
.PP
.nf
          EST is REAL
         On entry with KASE = 1 or 2 and ISAVE(1) = 3, EST should be
         unchanged from the previous call to CLACN2\&.
         On exit, EST is an estimate (a lower bound) for norm(A)\&.
.fi
.PP
.br
\fIKASE\fP 
.PP
.nf
          KASE is INTEGER
         On the initial call to CLACN2, KASE should be 0\&.
         On an intermediate return, KASE will be 1 or 2, indicating
         whether X should be overwritten by A * X  or A**H * X\&.
         On the final return from CLACN2, KASE will again be 0\&.
.fi
.PP
.br
\fIISAVE\fP 
.PP
.nf
          ISAVE is INTEGER array, dimension (3)
         ISAVE is used to save variables between calls to SLACN2
.fi
.PP
 
.RE
.PP
\fBAuthor\fP
.RS 4
Univ\&. of Tennessee 
.PP
Univ\&. of California Berkeley 
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Univ\&. of Colorado Denver 
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NAG Ltd\&. 
.RE
.PP
\fBFurther Details:\fP
.RS 4

.PP
.nf
  Originally named CONEST, dated March 16, 1988\&.

  Last modified:  April, 1999

  This is a thread safe version of CLACON, which uses the array ISAVE
  in place of a SAVE statement, as follows:

     CLACON     CLACN2
      JUMP     ISAVE(1)
      J        ISAVE(2)
      ITER     ISAVE(3)
.fi
.PP
 
.RE
.PP
\fBContributors:\fP
.RS 4
Nick Higham, University of Manchester 
.RE
.PP
\fBReferences:\fP
.RS 4
N\&.J\&. Higham, 'FORTRAN codes for estimating the one-norm of
  a real or complex matrix, with applications to condition estimation', ACM Trans\&. Math\&. Soft\&., vol\&. 14, no\&. 4, pp\&. 381-396, December 1988\&. 
.RE
.PP

.PP
Definition at line \fB132\fP of file \fBclacn2\&.f\fP\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.