LORENE
zero_list.C
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/*
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* Function zero_list
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* Locates approximatively all the zeros of a function in a given interval
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*
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* (see file utilitaires.h for documentation)
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*
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*/
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/*
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* Copyright (c) 2003 Eric Gourgoulhon
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*
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* This file is part of LORENE.
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*
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* LORENE is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* LORENE is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with LORENE; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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char
zero_list_C[] =
"$Header: /cvsroot/Lorene/C++/Source/Non_class_members/Utilities/zero_list.C,v 1.2 2014/10/13 08:53:32 j_novak Exp $"
;
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/*
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* $Id: zero_list.C,v 1.2 2014/10/13 08:53:32 j_novak Exp $
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* $Log: zero_list.C,v $
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* Revision 1.2 2014/10/13 08:53:32 j_novak
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* Lorene classes and functions now belong to the namespace Lorene.
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*
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* Revision 1.1 2003/09/08 20:22:02 e_gourgoulhon
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* First version
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*
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*
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* $Header: /cvsroot/Lorene/C++/Source/Non_class_members/Utilities/zero_list.C,v 1.2 2014/10/13 08:53:32 j_novak Exp $
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*
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*/
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// Headers Lorene
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#include "param.h"
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#include "tbl.h"
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//****************************************************************************
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namespace
Lorene
{
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void
zero_list
(
double
(*
f
)(
double
,
const
Param
&),
const
Param
&
par
,
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double
xmin,
double
xmax,
int
nsub
,
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Tbl
*&
az
,
Tbl
*&
bz
) {
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int
nzero
= 0 ;
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double
dx
= (xmax-xmin) /
double
(
nsub
) ;
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double
f1
=
f
(xmin,
par
) ;
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double
x1
= xmin ;
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double
x2
= xmin +
dx
;
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double
*
borne_inf
=
new
double
[
nsub
] ;
// At maximum nsub zeros
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double
*
borne_sup
=
new
double
[
nsub
] ;
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for
(
int
i
=0;
i
<
nsub
;
i
++) {
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double
f2
=
f
(
x2
,
par
) ;
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if
(
f1
*
f2
< 0.) {
// A zero has been found
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borne_inf
[
nzero
] =
x1
;
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borne_sup
[
nzero
] =
x2
;
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nzero
+= 1 ;
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}
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// Next sub-interval :
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x1
=
x2
;
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f1
=
f2
;
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x2
+=
dx
;
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}
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// Result:
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az
=
new
Tbl
(
nzero
) ;
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bz
=
new
Tbl
(
nzero
) ;
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if
(
nzero
> 0) {
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az
->set_etat_qcq() ;
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bz
->set_etat_qcq() ;
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for
(
int
i
=0;
i
<
nzero
;
i
++) {
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az
->set(
i
) =
borne_inf
[
i
] ;
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bz
->set(
i
) =
borne_sup
[
i
] ;
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}
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}
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delete
[]
borne_inf
;
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delete
[]
borne_sup
;
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}
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}
Lorene::Evolution_std
Time evolution with partial storage (*** under development ***).
Definition
evolution.h:371
Lorene::Param
Parameter storage.
Definition
param.h:125
Lorene::Tbl
Basic array class.
Definition
tbl.h:161
Lorene::zero_list
void zero_list(double(*f)(double, const Param &), const Param &par, double xmin, double xmax, int nsub, Tbl *&az, Tbl *&bz)
Locates approximatively all the zeros of a function in a given interval.
Definition
zero_list.C:57
Lorene
Lorene prototypes.
Definition
app_hor.h:64
C++
Source
Non_class_members
Utilities
zero_list.C
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