zone_cut.cpp

/*
    Copyright 2017 Philippe Grandclement
 
    This file is part of Kadath.
 
    Kadath is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    Kadath is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with Kadath.  If not, see <http://www.gnu.org/licenses/>.
*/
 
#include "headcpp.hpp"
#include "utilities.hpp"
#include "param.hpp"
 
namespace Kadath {
double feta_zero (double eta, const Param& par) {
    double chi = par.get_double(0) ;
    double rsa = par.get_double(1) ;
    double denom = (cosh(eta)-cos(chi)) ;
    return ((sinh(eta)*sinh(eta)+sin(chi)*sin(chi))/denom/denom-rsa*rsa) ;
}
 
 
double eta_lim_chi (double chi, double rext, double a, double eta_c) {
    double res ;
    Param par_func ;
    par_func.add_double(chi, 0) ;
    par_func.add_double(rext/a,1) ;
    double precis = PRECISION ;
    int nitermax = 500 ;
    int niter ;
    
    if (chi<=PRECISION)
        res = eta_c ;
    else 
        res = zerosec(feta_zero, par_func, 0, eta_c, precis, nitermax, niter) ;
    return res ;
}
 
double fchi_zero (double chi, const Param& par) {
    double eta = par.get_double(0) ;
    double rsa = par.get_double(1) ;
    double denom = (cosh(eta)-cos(chi)) ;
    return ((sinh(eta)*sinh(eta)+sin(chi)*sin(chi))/denom/denom-rsa*rsa) ;
}
 
 
double chi_lim_eta (double eta, double rext, double a, double chi_c) {
    double res ;
    Param par_func ;
    par_func.add_double(eta, 0) ;
    par_func.add_double(rext/a,1) ;
    double precis = PRECISION ;
    int nitermax = 500 ;
    int niter ;
    if (fabs(eta)<=PRECISION)
        res = chi_c ;
    else 
        res = zerosec(fchi_zero, par_func, 0, chi_c, precis, nitermax, niter) ;
    return res ;
}}