PrecessWaveformTest.c

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/*
 *  Copyright (C) 2012 Chris Pankow, Evan Ochsner
 *
 *  This program 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 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 with program; see the file COPYING. If not, write to the
 *  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 *  MA  02110-1301  USA
 */
 
/**
 * \author Chris Pankow
 *
 * \file
 *
 * \brief Testing constant precession code on TaylorT1 waveform.
 */
 
 
#include <lal/LALSimInspiralPrecess.h>
 
int main(void){
 
  FILE* h_ref = fopen("h_ref.txt", "w");
  FILE* h_rot = fopen("h_rot.txt", "w");
  REAL8TimeSeries *hp = NULL, *hx = NULL;
 
  int ret;
  unsigned int i;
 
  // Waveform parameters
  REAL8 m1 = 2.0*LAL_MSUN_SI, m2 = 5.0*LAL_MSUN_SI;
  REAL8 f_min = 40.0, f_ref = 0., dist = 1e6*LAL_PC_SI;
  REAL8 dt = 1/16384.0;
  REAL8 inclination = LAL_PI_4, psi = 0.;
  int Lmax = 5;
  LALDict *LALpars=XLALCreateDict();
  Approximant approximant = TaylorT1;
 
  // Parameters define a constant precession cone
  REAL8 precess_freq = 10.; // Freq. of L's motion about cone (Hz)
  REAL8 cone_opening = LAL_PI_4; // Opening angle of precession cone
  REAL8 cone_azimuth = 0.; // Initial azimuthal angle of L on its cone
  REAL8 J_azimuth = 0.;//azimuth btwn center of cone (J) and line of sight
  REAL8 J_zenith = inclination; // zenith angle btwn J and line of sight
 
  // Generate all available waveform modes
  SphHarmTimeSeries *ts = XLALSimInspiralChooseTDModes(0.,
    dt,
    m1, m2,
    0., 0., 0., 0., 0., 0.,
    f_min, f_ref,
    dist,
    LALpars,
    Lmax,
    approximant
    );
 
  // Generate the unrotated polarizations from the modes
  ret = XLALSimInspiralPolarizationsFromSphHarmTimeSeries(&hp, &hx, ts,
                                                          inclination, psi);
  if( ret != XLAL_SUCCESS ) XLAL_ERROR( XLAL_EFUNC );
 
  // Write out unrotated polarizations
  REAL8 t0 = XLALGPSGetREAL8(&(hp->epoch));
  for(i=0; i<hp->data->length; i++)
    fprintf( h_ref, "%.16g %.16g %.16g\n", t0 + i * hp->deltaT,
             hp->data->data[i], hx->data->data[i] );
 
  // Transform waveform so L moves on a constant precession cone
  ret = XLALSimInspiralConstantPrecessionConeWaveform(
    &hp, &hx,
    ts,
    precess_freq,
    cone_opening, cone_azimuth,
    J_azimuth, J_zenith );
  if( ret != XLAL_SUCCESS ) XLAL_ERROR( XLAL_EFUNC );
 
  XLALDestroySphHarmTimeSeries( ts );
 
  // Write out rotated waveform
  for(i=0; i<hp->data->length; i++)
    fprintf( h_rot, "%.16g %.16g %.16g\n", t0 + i * hp->deltaT,
             hp->data->data[i], hx->data->data[i] );
 
  // We're done.
  XLALDestroyDict(LALpars);
  XLALDestroyREAL8TimeSeries( hp );
  XLALDestroyREAL8TimeSeries( hx );
 
  fclose(h_ref);
  fclose(h_rot);
 
  return 0;
}