# zlacon(3) [centos man page]

```zlacon.f(3)							      LAPACK							       zlacon.f(3)

NAME
zlacon.f -

SYNOPSIS
Functions/Subroutines
subroutine zlacon (N, V, X, EST, KASE)
ZLACON estimates the 1-norm of a square matrix, using reverse communication for evaluating matrix-vector products.

Function/Subroutine Documentation
subroutine zlacon (integerN, complex*16, dimension( n )V, complex*16, dimension( n )X, double precisionEST, integerKASE)
ZLACON estimates the 1-norm of a square matrix, using reverse communication for evaluating matrix-vector products.

Purpose:

ZLACON estimates the 1-norm of a square, complex matrix A.
Reverse communication is used for evaluating matrix-vector products.

Parameters:
N

N is INTEGER
The order of the matrix.  N >= 1.

V

V is COMPLEX*16 array, dimension (N)
On the final return, V = A*W,  where  EST = norm(V)/norm(W)
(W is not returned).

X

X is COMPLEX*16 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 ZLACON must be
re-called with all the other parameters unchanged.

EST

EST is DOUBLE PRECISION
On entry with KASE = 1 or 2 and JUMP = 3, EST should be
unchanged from the previous call to ZLACON.
On exit, EST is an estimate (a lower bound) for norm(A).

KASE

KASE is INTEGER
On the initial call to ZLACON, 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 ZLACON, KASE will again be 0.

Author:
Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Date:
September 2012

Further Details:
Originally named CONEST, dated March 16, 1988.

Contributors:
Nick Higham, University of Manchester

References:
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.

Definition at line 115 of file zlacon.f.

Author
Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2							  Tue Sep 25 2012						       zlacon.f(3)```

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```zlacon.f(3)							      LAPACK							       zlacon.f(3)

NAME
zlacon.f -

SYNOPSIS
Functions/Subroutines
subroutine zlacon (N, V, X, EST, KASE)
ZLACON

Function/Subroutine Documentation
subroutine zlacon (integerN, complex*16, dimension( n )V, complex*16, dimension( n )X, double precisionEST, integerKASE)
ZLACON

Purpose:

ZLACON estimates the 1-norm of a square, complex matrix A.
Reverse communication is used for evaluating matrix-vector products.

Parameters:
N

N is INTEGER
The order of the matrix.  N >= 1.

V

V is COMPLEX*16 array, dimension (N)
On the final return, V = A*W,  where  EST = norm(V)/norm(W)
(W is not returned).

X

X is COMPLEX*16 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 ZLACON must be
re-called with all the other parameters unchanged.

EST

EST is DOUBLE PRECISION
On entry with KASE = 1 or 2 and JUMP = 3, EST should be
unchanged from the previous call to ZLACON.
On exit, EST is an estimate (a lower bound) for norm(A).

KASE

KASE is INTEGER
On the initial call to ZLACON, 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 ZLACON, KASE will again be 0.

Author:
Univ. of Tennessee

Univ. of California Berkeley

NAG Ltd.

Date:
November 2011

Further Details:
Originally named CONEST, dated March 16, 1988.

Contributors:
Nick Higham, University of Manchester

References:
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.

Definition at line 115 of file zlacon.f.

Author
Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.1							  Sun May 26 2013						       zlacon.f(3)```
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