LORENE
zero_premier.C
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/*
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* Locates the first zero of a function in a given interval.
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*
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*/
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/*
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* Copyright (c) 1999-2001 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_premier_C[] =
"$Header: /cvsroot/Lorene/C++/Source/Non_class_members/Utilities/zero_premier.C,v 1.3 2014/10/13 08:53:32 j_novak Exp $"
;
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/*
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* $Id: zero_premier.C,v 1.3 2014/10/13 08:53:32 j_novak Exp $
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* $Log: zero_premier.C,v $
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* Revision 1.3 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 1.2 2002/10/16 14:37:12 j_novak
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* Reorganization of #include instructions of standard C++, in order to
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* use experimental version 3 of gcc.
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*
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* Revision 1.1.1.1 2001/11/20 15:19:29 e_gourgoulhon
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* LORENE
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*
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* Revision 1.2 2000/01/04 10:57:51 eric
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* Le test f1*f2 < 0. est remplace par f1*f2 <= double(0).
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*
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* Revision 1.1 1999/12/24 13:00:10 eric
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* Initial revision
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*
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*
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* $Header: /cvsroot/Lorene/C++/Source/Non_class_members/Utilities/zero_premier.C,v 1.3 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 "headcpp.h"
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#include "param.h"
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//****************************************************************************
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namespace
Lorene
{
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bool
zero_premier
(
double
(*
f
)(
double
,
const
Param
&),
const
Param
&
par
,
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double
a
,
double
b,
int
n
,
double
&
a0
,
double
&
b0
) {
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double
dx
= (b-
a
)/
double
(
n
) ;
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a0
=
a
;
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b0
=
a0
+
dx
;
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double
f1
=
f
(
a0
,
par
) ;
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bool
trouve
=
false
;
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for
(
int
i
=0;
i
<
n
;
i
++) {
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double
f2
=
f
(
b0
,
par
) ;
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if
(
f1
*
f2
<=
double
(0)) {
// on a encadre le zero
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trouve
=
true
;
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break
;
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}
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// On passe au sous-intervalle suivant :
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a0
=
b0
;
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f1
=
f2
;
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b0
+=
dx
;
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}
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return
trouve
;
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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::zero_premier
bool zero_premier(double(*f)(double, const Param &), const Param &par, double a, double b, int n, double &a0, double &b0)
Locates the sub-interval containing the first zero of a function in a given interval.
Definition
zero_premier.C:61
Lorene
Lorene prototypes.
Definition
app_hor.h:64
C++
Source
Non_class_members
Utilities
zero_premier.C
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