bin_ns_bh_orbit.C

/*
 *  Method of class Bin_ns_bh to compute the orbital angular velocity
 *  {\tt omega}
 *
 *    (see file bin_ns_bh.h for documentation).
 *
 */

/*
 *   Copyright (c) 2003 Keisuke Taniguchi
 *
 *   This file is part of LORENE.
 *
 *   LORENE is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License version 2
 *   as published by the Free Software Foundation.
 *
 *   LORENE 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 LORENE; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

char bin_ns_bh_orbit_C[] = "$Header: /cvsroot/Lorene/C++/Source/Bin_ns_bh/bin_ns_bh_orbit.C,v 1.4 2004/06/09 07:26:16 k_taniguchi Exp $" ;

/*
 * $Id: bin_ns_bh_orbit.C,v 1.4 2004/06/09 07:26:16 k_taniguchi Exp $
 * $Log: bin_ns_bh_orbit.C,v $
 * Revision 1.4  2004/06/09 07:26:16  k_taniguchi
 * Minor changes.
 *
 * Revision 1.3  2004/06/09 06:20:11  k_taniguchi
 * Set the standard basis for some Cmp.
 *
 * Revision 1.2  2004/03/25 10:28:58  j_novak
 * All LORENE's units are now defined in the namespace Unites (in file unites.h).
 *
 * Revision 1.1  2003/10/24 16:57:43  k_taniguchi
 * Method for the calculation of the orbital angular velocity
 *
 *
 * $Header: /cvsroot/Lorene/C++/Source/Bin_ns_bh/bin_ns_bh_orbit.C,v 1.4 2004/06/09 07:26:16 k_taniguchi Exp $
 *
 */

// C headers
#include <math.h>

// Lorene headers
#include "bin_ns_bh.h"
#include "eos.h"
#include "param.h"
#include "utilitaires.h"
#include "unites.h"

double  fonc_bin_ns_bh_orbit(double , const Param& ) ;

//*************************************************************************

void Bin_ns_bh::orbit_omega(double fact_omeg_min, double fact_omeg_max) {

  using namespace Unites ; 

    //------------------------------------------------------------------
    // Evaluation of various quantities at the center of a neutron star
    //------------------------------------------------------------------

    double dnulg, asn2, dasn2, ny, dny, npn, dnpn ;

    const Map& mp = star.get_mp() ;

    const Cmp& loggam = star.get_loggam()() ;
    const Cmp& nnn = star.get_nnn()() ;
    const Cmp& confpsi = star.get_confpsi()() ;
    const Tenseur& shift = star.get_shift() ;

    Cmp confpsi_q = pow(confpsi, 4.) ;
    confpsi_q.std_base_scal() ;

    //-----------------------------------------------------------------
    // Calculation of d/dX( nu + ln(Gamma) ) at the center of the star
    //  ---> dnulg
    //-----------------------------------------------------------------

    // Factor for the coordinate transformation x --> X :
    double factx ;
    if (fabs(mp.get_rot_phi()) < 1.e-14) {
    factx = 1. ;
    }
    else {
    if (fabs(mp.get_rot_phi() - M_PI) < 1.e-14) {
        factx = - 1. ;
    }
    else {
        cout << "Bin_ns_bh::orbit_omega : unknown value of rot_phi !"
         << endl ;
        abort() ;
    }
    }

    Cmp tmp = log( nnn ) + loggam ;
    tmp.std_base_scal() ;

    // ... gradient
    dnulg = factx * tmp.dsdx()(0, 0, 0, 0) ;

    //------------------------------------------------------------
    // Calculation of A^2/N^2 at the center of the star ---> asn2
    //------------------------------------------------------------
    double nc = nnn(0, 0, 0, 0) ;
    double a2c = confpsi_q(0, 0, 0, 0) ;
    asn2 = a2c / (nc * nc) ;

    if ( star.is_relativistic() ) {

    //------------------------------------------------------------------
    // Calculation of d/dX(A^2/N^2) at the center of the star ---> dasn
    //------------------------------------------------------------------
    double da2c = factx * confpsi_q.dsdx()(0, 0, 0, 0) ;
    double dnc =  factx * nnn.dsdx()(0, 0, 0, 0) ;

    dasn2 = ( da2c - 2 * a2c / nc * dnc ) / (nc*nc) ;

    //------------------------------------------------------
    // Calculation of N^Y at the center of the star ---> ny
    //------------------------------------------------------
    ny = shift(1)(0, 0, 0, 0) ;

    //-----------------------------------------------------------
    // Calculation of dN^Y/dX at the center of the star ---> dny
    //-----------------------------------------------------------
    dny = factx * shift(1).dsdx()(0, 0, 0, 0) ;

    //--------------------------------------------
    // Calculation of (N^X)^2 + (N^Y)^2 + (N^Z)^2
    //  at the center of the star ---> npn
    //--------------------------------------------
    tmp = flat_scalar_prod(shift, shift)() ;
    npn = tmp(0, 0, 0, 0) ;

    //----------------------------------------------------
    // Calculation of d/dX( (N^X)^2 + (N^Y)^2 + (N^Z)^2 )
    //  at the center of the star ---> dnpn
    //----------------------------------------------------
    dnpn = factx * tmp.dsdx()(0, 0, 0, 0) ;

    }  // Finish of the relativistic case
    else {
    cout << "Bin_ns_bh::orbit_omega : "
         << "It should be the relativistic calculation !" << endl ;
    abort() ;
    }

    cout << "Bin_ns_bh::orbit_omega: central d(nu+log(Gam))/dX : " 
     << dnulg << endl ; 
    cout << "Bin_ns_bh::orbit_omega: central A^2/N^2 : " << asn2 << endl ; 
    cout << "Bin_ns_bh::orbit_omega: central d(A^2/N^2)/dX : "
     << dasn2 << endl ; 
    cout << "Bin_ns_bh::orbit_omega: central N^Y : " << ny << endl ; 
    cout << "Bin_ns_bh::orbit_omega: central dN^Y/dX : " << dny << endl ; 
    cout << "Bin_ns_bh::orbit_omega: central N.N : " << npn << endl ; 
    cout << "Bin_ns_bh::orbit_omega: central d(N.N)/dX : "
     << dnpn << endl ; 

    //------------------------------------------------------
    // Start of calculation of the orbital angular velocity
    //------------------------------------------------------
    int relat = ( star.is_relativistic() ) ? 1 : 0 ;

    Param parf ;
    parf.add_int(relat) ;
    parf.add_double( (star.get_mp()).get_ori_x(), 0) ;
    parf.add_double( dnulg, 1) ;
    parf.add_double( asn2, 2) ;
    parf.add_double( dasn2, 3) ;
    parf.add_double( ny, 4) ;
    parf.add_double( dny, 5) ;
    parf.add_double( npn, 6) ;
    parf.add_double( dnpn, 7) ;
    parf.add_double( x_axe, 8) ;

    double omega1 = fact_omeg_min * omega ;
    double omega2 = fact_omeg_max * omega ;

    cout << "Bin_ns_bh::orbit_omega: omega1, omega2 [rad/s] : "
     << omega1 * f_unit << "  " << omega2 * f_unit << endl ;

    // Search for the various zeros in the interval [omega1,omega2]
    // ------------------------------------------------------------
    int nsub = 50 ;  // total number of subdivisions of the interval
    Tbl* azer = 0x0 ;
    Tbl* bzer = 0x0 ;
    zero_list(fonc_bin_ns_bh_orbit, parf, omega1, omega2, nsub,
          azer, bzer) ;

    // Search for the zero closest to the previous value of omega
    // ----------------------------------------------------------
    double omeg_min, omeg_max ;
    int nzer = azer->get_taille() ; // number of zeros found by zero_list
    cout << "Bin_ns_bh:orbit_omega : " << nzer <<
    "zero(s) found in the interval [omega1,  omega2]." << endl ;
    cout << "omega, omega1, omega2 : " << omega << "  " << omega1
     << "  " << omega2 << endl ; 
    cout << "azer : " << *azer << endl ;
    cout << "bzer : " << *bzer << endl ;

    if (nzer == 0) {
    cout << "Bin_ns_bh::orbit_omega: WARNING : "
         << "no zero detected in the interval" << endl
         << "   [" << omega1 * f_unit << ", " 
         << omega2 * f_unit << "]  rad/s  !" << endl ;
    omeg_min = omega1 ;
    omeg_max = omega2 ;
    }
    else {
    double dist_min = fabs(omega2 - omega1) ;
    int i_dist_min = -1 ;
    for (int i=0; i<nzer; i++) {
        // Distance of previous value of omega from the center of the
        //  interval [azer(i), bzer(i)]
        double dist = fabs( omega - 0.5 * ( (*azer)(i) + (*bzer)(i) ) ) ;

        if (dist < dist_min) {
        dist_min = dist ;
        i_dist_min = i ;
        }
    }
    omeg_min = (*azer)(i_dist_min) ;
    omeg_max = (*bzer)(i_dist_min) ;
    }

    delete azer ; // Tbl allocated by zero_list
    delete bzer ; //

    cout << "Bin_ns_bh:orbit_omega : "
     << "interval selected for the search of the zero : "
     << endl << "  [" << omeg_min << ", " << omeg_max << "] = ["
     << omeg_min * f_unit << ", " << omeg_max * f_unit << "] rad/s "
     << endl ;

    // Computation of the zero in the selected interval by the secant method
    // ---------------------------------------------------------------------

    int nitermax = 200 ;
    int niter ;
    double precis = 1.e-13 ;
    omega = zerosec_b(fonc_bin_ns_bh_orbit, parf, omeg_min, omeg_max,
              precis, nitermax, niter) ;

    cout << "Bin_ns_bh::orbit_omega : "
     << "Number of iterations in zerosec for omega : "
     << niter << endl ;

    cout << "Bin_ns_bh::orbit_omega : omega [rad/s] : "
     << omega * f_unit << endl ;

}

//***********************************************************
//  Function used for search of the orbital angular velocity
//***********************************************************

double fonc_bin_ns_bh_orbit(double om, const Param& parf) {

    int relat = parf.get_int() ;

    double xc = parf.get_double(0) ;
    double dnulg = parf.get_double(1) ;
    double asn2 = parf.get_double(2) ;
    double dasn2 = parf.get_double(3) ;
    double ny = parf.get_double(4) ;
    double dny = parf.get_double(5) ;
    double npn = parf.get_double(6) ;
    double dnpn = parf.get_double(7) ;
    double x_axe = parf.get_double(8) ;

    double xx = xc - x_axe ;
    double om2 = om*om ;

    double dphi_cent ;

    if (relat == 1) {
    double bpb = om2 * xx*xx - 2*om * ny * xx + npn ;

    dphi_cent = ( asn2* ( om* (ny + xx*dny) - om2*xx - 0.5*dnpn )
             - 0.5*bpb* dasn2 )
               / ( 1 - asn2 * bpb ) ;
    }
    else {
    cout << "Bin_ns_bh::orbit_omega : "
         << "It should be the relativistic calculation !" << endl ;
    abort() ;
    }

    return dnulg + dphi_cent ;

}

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