particle_halo.h

//
//  particle_halo.h
//  GLAMER
//
//  Created by bmetcalf on 16/06/15.
//
//
 
#ifndef GLAMER_particle_halo_h
#define GLAMER_particle_halo_h
 
#include "geometry.h"
#include "quadTree.h"
#include "simpleTree.h"
#include "particle_types.h"
#include "utilities_slsim.h"
#include "lens_halos.h"
#include "quadTreeHalos.h"
 
template<typename PType>
class LensHaloParticles : public LensHalo
{
public:
  
  LensHaloParticles(const std::string& simulation_filename 
                    ,SimFileFormat format   
                    ,PosType redshift        
                    ,int Nsmooth             
                    ,const COSMOLOGY& cosmo  
                    ,Point_2d theta_rotate   
                    ,bool recenter           
                    ,bool my_multimass       
                    ,double inv_area           
                    ,PosType MinPSize=0        
                    ,PosType rescale_mass = 1.0   
                    ,bool verbose=false
  );
 
  LensHaloParticles(std::vector<PType> &pvector 
                    ,float redshift        
                    ,const COSMOLOGY& cosmo  
                    ,Point_2d theta_rotate   
                    ,bool recenter           
                    ,double my_inv_area           
                    ,float MinPSize = 0        
                    ,double max_range = -1
                    ,bool verbose=false
  ):LensHalo(redshift,cosmo),min_size(MinPSize),multimass(true),inv_area(my_inv_area)
  {
    Npoints = pvector.size();
   
    std::swap(pvector,trash_collector);
    pp = trash_collector.data();
  
    set_up(redshift,cosmo,theta_rotate,max_range,recenter,verbose);
  }
 
  LensHaloParticles(
                    PType *begin 
                    ,size_t n
                    ,float redshift        
                    ,const COSMOLOGY& cosmo  
                    ,Point_2d theta_rotate   
                    ,bool recenter           
                    ,double my_inv_area           
                    ,float MinPSize = 0        
                    ,double max_range = -1
                    ,bool verbose=false
  ):LensHalo(redshift,cosmo),min_size(MinPSize),multimass(true),inv_area(my_inv_area),Npoints(n)
  {
    pp = begin;
    set_up(redshift,cosmo,theta_rotate,max_range,recenter,verbose);
  }
  ~LensHaloParticles();
  
  LensHaloParticles(LensHaloParticles &&h):LensHalo(std::move(h)){
    mcenter = h.mcenter;
    densest_point = h.densest_point;
    trash_collector =std::move(h.trash_collector);
    pp = trash_collector.data();
    h.pp = nullptr;
    
    min_size = h.min_size;
    multimass = h.multimass;
    center = h.center;
    Npoints = h.Npoints;
    simfile = h.simfile;
    sizefile = h.sizefile;
    inv_area = h.inv_area;
    
    qtree = h.qtree;
    h.qtree = nullptr;
  }
  LensHaloParticles<PType> & operator=(LensHaloParticles<PType> &&h);
 
 
  void force_halo(double *alpha,KappaType *kappa,KappaType *gamma,KappaType *phi,double const *xcm
                  ,bool subtract_point=false,PosType screening = 1.0);
 
  size_t getN() const { return Npoints; };
  
  void rotate(Point_2d theta);
  
   Point_3d<> CenterOfMass(){return mcenter;}
   Point_3d<> DensestPoint(){return densest_point;}
 
  static void makeSIE(
                      std::string new_filename  
                      ,PosType redshift     
                      ,double particle_mass 
                      ,double total_mass  
                      ,double sigma       
                      ,double q  
                      ,Utilities::RandomNumbers_NR &ran
                      );
  
  static LensHaloParticles<ParticleTypeSimple> SIE(
            PosType redshift     
            ,double particle_mass 
            ,double total_mass  
            ,double sigma       
            ,double q  
            ,int Nneighbors  
            ,COSMOLOGY &cosmo
            ,Utilities::RandomNumbers_NR &ran);
 
  
  static void calculate_smoothing(int Nsmooth
                                  ,PType *pp
                                  ,size_t Npoints
                                  ,bool verbose = false);
  
  void readPositionFileASCII(const std::string &filename);
  
  static void writeSizes(const std::string &filename
                         ,int Nsmooth
                         ,const PType *pp
                         ,size_t Npoints
                         );
 
  static bool readSizesFile(const std::string &filename
                            ,PType * pp
                            ,size_t Npoints
                            ,int Nsmooth
                            ,PosType min_size);
 
  friend class MakeParticleLenses;
  
protected:
  // constructure for derived classes
  LensHaloParticles(float redshift        
                    ,const COSMOLOGY& cosmo  
  ): LensHalo(redshift,cosmo){}
 
  // This constructor is really only for use by MakeParticleLenses. It does not take
  // possession of the data and so they will not be deleted on destruction
  LensHaloParticles(PType  *pdata          
                    ,size_t Nparticles
                    ,float redshift        
                    ,const COSMOLOGY& cosmo  
                    ,Point_2d theta_rotate   
                    ,bool recenter           
                    ,double my_inv_area           
                    ,bool verbose = false
  ):LensHalo(redshift,cosmo),pp(pdata),min_size(0),multimass(true),Npoints(Nparticles),inv_area(my_inv_area)
  {
    set_up(redshift,cosmo,theta_rotate,-1,recenter,verbose);
  }
  
  void rotate_particles(PosType theta_x,PosType theta_y);
  static void smooth_(TreeSimple<PType> *tree3d,PType *xp,size_t N,int Nsmooth);
  void assignParams(InputParams& params);
 
  Point_3d<> mcenter;
  Point_3d<> densest_point;
  
  PType *pp;
  std::vector<PType> trash_collector;
  
  PosType min_size;  // minimum allowed size
  bool multimass;
  
  Utilities::Geometry::SphericalPoint<> center;
  
  size_t Npoints;
  PosType inv_area;
  
  std::string simfile;
  std::string sizefile;
  
  
  TreeQuadParticles<PType> * qtree;
  void set_up(float redshift,const COSMOLOGY& cosmo,Point_2d theta_rotate,double max_range,bool recenter,bool verbose);
};
 
template<typename PType>
LensHaloParticles<PType>::LensHaloParticles(const std::string& simulation_filename
                                            ,SimFileFormat format
                                            ,PosType redshift
                                            ,int Nsmooth
                                            ,const COSMOLOGY& cosmo
                                            ,Point_2d theta_rotate
                                            ,bool recenter
                                            ,bool my_multimass
                                            ,double my_inv_area
                                            ,PosType MinPSize
                                            ,PosType massscaling
                                            ,bool verbose
                                            )
:LensHalo(redshift,cosmo),min_size(MinPSize),multimass(my_multimass),simfile(simulation_filename),inv_area(my_inv_area)
{
  
  LensHalo::setZlens(redshift,cosmo);
  LensHalo::setCosmology(cosmo);
  LensHalo::set_flag_elliptical(false);
  
  //stars_N = 0;
  //stars_implanted = false;
  
  Rmax = 1.0e3;
  LensHalo::setRsize(Rmax);
  
  switch (format) {
    case  SimFileFormat::ascii:
      readPositionFileASCII(simulation_filename);
      break;
    default:
      std::cerr << "LensHaloParticles does not accept format of particle data file." << std::endl;
      throw std::invalid_argument("bad format");
  }
  
  sizefile = simfile + "." + std::to_string(Nsmooth) + "sizes";
  
  if(!readSizesFile(sizefile,pp,Npoints,Nsmooth,min_size)){
    
    // calculate sizes
    calculate_smoothing(Nsmooth,pp,Npoints);
    
    // save result to a file for future use
    writeSizes(sizefile,Nsmooth,pp,Npoints);
    //for(size_t i=0; i<Npoints ; ++i) if(sizes[i] < min_size) sizes[i] = min_size;
    for(size_t i=0; i<Npoints ; ++i) if(pp[i].size() < min_size) pp[i].Size = min_size;
  }
  
  double min_s = pp[0].Size;
  size_t smallest_part = 0;
  for(size_t i = 1 ; i<Npoints ; ++i){
    if(pp[i].Size < min_s){
      min_s = pp[i].Size;
      smallest_part = i;
    }
    pp[i].Mass *= massscaling;
  }
  
  densest_point[0] = pp[smallest_part].x[0];
  densest_point[1] = pp[smallest_part].x[1];
  densest_point[2] = pp[smallest_part].x[2];
 
  
  // convert from comoving to physical coordinates
  PosType scale_factor = 1/(1+redshift);
  mcenter *= 0.0;
  PosType max_mass = 0.0,min_mass = HUGE_VALF,mass=0;
  for(size_t i=0;i<Npoints;++i){
    pp[i][0] *= scale_factor;
    pp[i][1] *= scale_factor;
    pp[i][2] *= scale_factor;
    
    mcenter[0] += pp[i][0]*pp[multimass*i].mass();
    mcenter[1] += pp[i][1]*pp[multimass*i].mass();
    mcenter[2] += pp[i][2]*pp[multimass*i].mass();
    
    mass += pp[multimass*i].mass();
    
    max_mass = (pp[multimass*i].mass() > max_mass) ? pp[multimass*i].mass() : max_mass;
    min_mass = (pp[multimass*i].mass() < min_mass) ? pp[multimass*i].mass() : min_mass;
  }
  LensHalo::setMass(mass);
  
  mcenter /= mass;
  
  if(verbose) std::cout << "   Particle mass range : " << min_mass << " to " << max_mass << "  ratio of : " << max_mass/min_mass << std::endl;
  
  
  if(recenter){
    PosType r2,r2max=0;
    for(size_t i=0;i<Npoints;++i){
      pp[i][0] -= mcenter[0];
      pp[i][1] -= mcenter[1];
      pp[i][2] -= mcenter[2];
      
      r2 = pp[i][0]*pp[i][0] + pp[i][1]*pp[i][1] + pp[i][2]*pp[i][2];
      if(r2 > r2max) r2max = r2;
    }
    
    LensHalo::setRsize( sqrt(r2max) );
    
    densest_point -= mcenter;
    
    mcenter *= 0;
  }
  
  // rotate positions
  rotate_particles(theta_rotate[0],theta_rotate[1]);
  
  qtree = new TreeQuadParticles<PType>(pp,Npoints,-1,-1,inv_area,20);
  
}
 
template<typename PType>
void LensHaloParticles<PType>::set_up(
                                 float redshift        
                                 ,const COSMOLOGY& cosmo  
                                 ,Point_2d theta_rotate   
                                 ,double max_range
                                 ,bool recenter           
                                 ,bool verbose
){
 
  //LensHalo::setZlens(redshift);
  //LensHalo::setCosmology(cosmo);
  LensHalo::set_flag_elliptical(false);
  
  //stars_N = 0;
  //stars_implanted = false;
  
  Rmax = 1.0e100;
  LensHalo::setRsize(Rmax);
  
  double min_s = pp[0].Size;
  size_t smallest_part = 0;
  for(size_t i =0 ; i<Npoints ; ++i){
    if(pp[i].Size < min_s){
      min_s = pp[i].Size;
      smallest_part = i;
    }
  }
  
  densest_point[0] = pp[smallest_part].x[0];
  densest_point[1] = pp[smallest_part].x[1];
  densest_point[2] = pp[smallest_part].x[2];
 
  // convert from comoving to physical coordinates
  //PosType scale_factor = 1/(1+redshift);
  mcenter *= 0.0;
  PosType max_mass = 0.0,min_mass = HUGE_VALF,mass=0;
  for(size_t i=0;i<Npoints;++i){
  
    mcenter[0] += pp[i][0]*pp[i].mass();
    mcenter[1] += pp[i][1]*pp[i].mass();
    mcenter[2] += pp[i][2]*pp[i].mass();
    
    mass += pp[i].mass();
    
    max_mass = (pp[i].mass() > max_mass) ? pp[i].mass() : max_mass;
    min_mass = (pp[i].mass() < min_mass) ? pp[i].mass() : min_mass;
  }
  LensHalo::setMass(mass);
  
  mcenter /= mass;
  
  if(verbose) std::cout << "   Particle mass range : " << min_mass << " to " << max_mass << "  ratio of : " << max_mass/min_mass << std::endl;
  
  if(recenter){
    PosType r2,r2max=0;
    for(size_t i=0;i<Npoints;++i){
      pp[i][0] -= mcenter[0];
      pp[i][1] -= mcenter[1];
      pp[i][2] -= mcenter[2];
      
      r2 = pp[i][0]*pp[i][0] + pp[i][1]*pp[i][1] + pp[i][2]*pp[i][2];
      if(r2 > r2max) r2max = r2;
      
      densest_point -= mcenter;
      
      mcenter *= 0;
    }
    
    LensHalo::setRsize( sqrt(r2max) );
  }
  
  // rotate positions
  rotate_particles(theta_rotate[0],theta_rotate[1]);
  
  qtree = new TreeQuadParticles<PType>(pp,Npoints,-1,-1,inv_area,20,0.1,false,max_range);
}
 
 
 
template<typename PType>
LensHaloParticles<PType>::~LensHaloParticles(){
  delete qtree;
}
 
template<typename PType>
void LensHaloParticles<PType>::force_halo(double *alpha,KappaType *kappa,KappaType *gamma,KappaType *phi
                                          ,double const *xcm
                                          ,bool subtract_point,PosType screening){
  qtree->force2D_recur(xcm,alpha,kappa,gamma,phi);
  
  alpha[0] *= -1;
  alpha[1] *= -1;
}
 
template<typename PType>
void LensHaloParticles<PType>::rotate(Point_2d theta){
  rotate_particles(theta[0],theta[1]);
  delete qtree;
 
  qtree = new TreeQuadParticles<ParticleType<float> >(pp,Npoints,-1,-1,inv_area,20);
}
 
template<typename PType>
void LensHaloParticles<PType>::readPositionFileASCII(const std::string &filename
                                                     ){
  
  int ncoll = Utilities::IO::CountColumns(filename);
  if(!multimass && ncoll != 3 ){
    std::cerr << filename << " should have three columns!" << std::endl;
  }
  if(multimass && ncoll != 4 ){
    std::cerr << filename << " should have four columns!" << std::endl;
  }
  
  std::ifstream myfile(filename);
  
  //size_t Npoints = 0;
  
  // find number of particles
  
  if (myfile.is_open()){
    
    float tmp_mass = 0.0;
    std::string str,label;
    int count =0;
    while(std::getline(myfile, str)){
      std::stringstream ss(str);
      ss >> label;
      if(label == "#"){
        ss >> label;
        if(label == "nparticles"){
          ss >> Npoints;
          ++count;
        }
        if(!multimass){
          if(label == "mass"){
            ss >> tmp_mass;
            ++count;
          }
        }
      }else break;
      if(multimass && count == 1 ) break;
      if(!multimass && count == 2 ) break;
    }
    
    if(count == 0){
      if(multimass) std::cerr << "File " << filename << " must have the header lines: " << std::endl
        << "# nparticles   ****" << std::endl << "# mass   ****" << std::endl;
      if(!multimass) std::cerr << "File " << filename << " must have the header lines: " << std::endl
        << "# nparticles   ****" << std::endl;
      throw std::runtime_error("file reading error");
    }
    
    trash_collector.resize(Npoints);  // this is here just to make sure this is deleted
    pp = trash_collector.data();
    //xp = Utilities::PosTypeMatrix(Npoints,3);
    //if(multimass) masses.resize(Npoints);
    //else masses.push_back(tmp_mass);
    
    size_t row = 0;
    
    // read in particle positions
    if(!multimass){
      while(std::getline(myfile, str) && row < Npoints){
        if(str[0] == '#') continue; //for comments
        std::stringstream ss(str);
        
        ss >> pp[row][0];
        if(!(ss >> pp[row][1])) std::cerr << "3 columns are expected in line " << row
          << " of " << filename << std::endl;
        if(!(ss >> pp[row][2])) std::cerr << "3 columns are expected in line " << row
          << " of " << filename << std::endl;
        
        row++;
      }
    }else{
      while(std::getline(myfile, str) && row < Npoints){
        if(str[0] == '#') continue; //for comments
        std::stringstream ss(str);
        
        ss >> pp[row][0];
        if(!(ss >> pp[row][1])) std::cerr << "4 columns are expected in line " << row
          << " of " << filename << std::endl;
        if(!(ss >> pp[row][2])) std::cerr << "4 columns are expected in line " << row
          << " of " << filename << std::endl;
        if(!(ss >> pp[row].Mass)) std::cerr << "4 columns are expected in line " << row
          << " of " << filename << std::endl;
        
        row++;
      }
    }
    
    if(row != Npoints){
      std::cerr << "Number of data rows in " << filename << " does not match expected number of particles."
      << std::endl;
      throw std::runtime_error("file reading error");
    }
  }else{
    std::cerr << "Unable to open file " << filename << std::endl;
    throw std::runtime_error("file reading error");
  }
  
  std::cout << Npoints << " particle positions read from file " << filename << std::endl;
  
}
 
template<typename PType>
bool LensHaloParticles<PType>::readSizesFile(const std::string &filename
                                             ,PType * pp
                                             ,size_t Npoints
                                             ,int Nsmooth
                                             ,PosType min_size){
  
  std::ifstream myfile(filename);
  
  // find number of particles
  
  PosType min=HUGE_VALF,max=0.0;
  if (myfile.is_open()){
    
    std::string str,label;
    int count =0;
    size_t Ntmp;
    int NStmp;
    while(std::getline(myfile, str)){
      std::stringstream ss(str);
      ss >> label;
      if(label == "#"){
        ss >> label;
        if(label == "nparticles"){
          ss >> Ntmp;
          if(Ntmp != Npoints){
            std::cerr << "Number of particles in " << filename << " does not match expected number" << std::endl;
            throw std::runtime_error("file reading error");
          }
          ++count;
        }
        if(label == "nsmooth"){
          ss >> NStmp;
          if(NStmp != Nsmooth) return false;
          ++count;
        }
        
      }else break;
      if(count == 2) break;
    }
    
    if(count != 2){
      std::cerr << "File " << filename << " must have the header lines: " << std::endl
      << "# nparticles   ****" << std::endl;
      throw std::runtime_error("file reading error");
    }
    
    size_t row = 0;
    
    std::cout << "reading in particle sizes from " << filename << "..." << std::endl;
    
    // read in particle sizes
    while(std::getline(myfile, str)){
      if(str[0] == '#') continue; //for comments
      std::stringstream ss(str);
      
      ss >> pp[row].Size;
      if(min_size > pp[row].size() ) pp[row].Size = min_size;
      min = min < pp[row].size() ? min : pp[row].size();
      max = max > pp[row].size() ? max : pp[row].size();
      row++;
    }
    
    if(row != Npoints){
      std::cerr << "Number of data rows in " << filename << " does not match expected number of particles."
      << std::endl;
      throw std::runtime_error("file reading error");
    }
  }else{
    return false;
  }
  
  std::cout << Npoints << " particle sizes read from file " << filename << std::endl;
  std::cout << "   maximun particle sizes " << max << " minimum " << min << " Mpc" << std::endl;
  
  return true;
}
 
template<typename PType>
void LensHaloParticles<PType>::rotate_particles(PosType theta_x,PosType theta_y){
  
  if(theta_x == 0.0 && theta_y == 0.0) return;
  
  PosType coord[3][3];
  PosType cx,cy,sx,sy;
  
  cx = cos(theta_x); sx = sin(theta_x);
  cy = cos(theta_y); sy = sin(theta_y);
  
  coord[0][0] = cy;  coord[1][0] = -sy*sx; coord[2][0] = cx;
  coord[0][1] = 0;   coord[1][1] = cx;     coord[2][1] = sx;
  coord[0][2] = -sy; coord[1][2] = -cy*sx; coord[2][2] = cy*cx;
  
  //PosType tmp[3];
  Point_3d<> tmp;
  int j;
  // rotate particle positions */
  for(size_t i=0;i<Npoints;++i){
    tmp *= 0;
    for(j=0;j<3;++j){
      tmp[0] += coord[0][j]*pp[i][j];
      tmp[1] += coord[1][j]*pp[i][j];
      tmp[2] += coord[2][j]*pp[i][j];
    }
    for(j=0;j<3;++j) pp[i][j]=tmp[j];
  }
  
  // rotate center of mass
  tmp *= 0.0;
  for(j=0;j<3;++j){
    tmp[0] += coord[0][j]*mcenter[j];
    tmp[1] += coord[1][j]*mcenter[j];
    tmp[2] += coord[2][j]*mcenter[j];
  }
  mcenter = tmp;
 
  // rotate center of mass
  tmp *= 0.0;
  for(j=0;j<3;++j){
    tmp[0] += coord[0][j]*densest_point[j];
    tmp[1] += coord[1][j]*densest_point[j];
    tmp[2] += coord[2][j]*densest_point[j];
  }
  densest_point = tmp;
}
 
template<typename PType>
void LensHaloParticles<PType>::calculate_smoothing(int Nsmooth,PType *pp
                                                   ,size_t Npoints
                                                   ,bool verbose
                                                   ){
  
  int nthreads = Utilities::GetNThreads();
  
  if(verbose) std::cout << "Calculating smoothing of particles ..." << std::endl
  << Nsmooth << " neighbors.  If there are a lot of particles this could take a while." << std::endl;
  
  time_t to,t;
  time(&to);
  
  // make 3d tree of particle postions
  TreeSimple<PType> tree3d(pp,Npoints,2*Nsmooth,3,true);
  // find distance to nth neighbour for every particle
  if(Npoints < 1000){
    //IndexType neighbors[Nsmooth];
    for(size_t i=0;i<Npoints;++i){
      pp[i].Size = tree3d.NNDistance(&pp[i][0],Nsmooth + 1);
    }
  }else{
    size_t chunksize = Npoints/nthreads;
    std::vector<std::thread> thr(nthreads);
    
    size_t N;
    for(int ii = 0; ii < nthreads ;++ii){
      if(ii == nthreads - 1){
        N = Npoints - ii*chunksize;
      }else N = chunksize;
      
      thr[ii] = std::thread(LensHaloParticles<PType>::smooth_,&tree3d
                            ,&(pp[ii*chunksize]),N,Nsmooth);
    }
    for(int ii = 0; ii < nthreads ;++ii) thr[ii].join();
  }
  time(&t);
  if(verbose) std::cout << "done in " << difftime(t,to) << " secs" << std::endl;
}
 
template<typename PType>
void LensHaloParticles<PType>::smooth_(TreeSimple<PType> *tree3d,PType *pp,size_t N,int Nsmooth){
  
  //IndexType neighbors[Nsmooth];
  for(size_t i=0;i<N;++i){
    pp[i].Size = tree3d->NNDistance(&(pp[i][0]),Nsmooth + 1);
  }
}
 
 
template<typename PType>
void LensHaloParticles<PType>::writeSizes(const std::string &filename,int Nsmooth
                                          ,const PType *pp,size_t Npoints
                                          ){
  
  std::ofstream myfile(filename);
  
  // find number of particles
  
  if (myfile.is_open()){
    
    std::cout << "Writing particle size information to file " << filename << " ...." << std::endl;
    
    myfile << "# nparticles " << Npoints << std::endl;
    myfile << "# nsmooth " << Nsmooth << std::endl;
    for(size_t i=0;i<Npoints;++i){
      myfile << pp[i].Size << std::endl;
      if(!myfile){
        std::cerr << "Unable to write to file " << filename << std::endl;
        throw std::runtime_error("file writing error");
      }
    }
    
    std::cout << "done" << std::endl;
    
  }else{
    std::cerr << "Unable to write to file " << filename << std::endl;
    throw std::runtime_error("file writing error");
  }
}
 
template<typename PType>
void LensHaloParticles<PType>::makeSIE(
                                       std::string new_filename  
                                       ,PosType redshift     
                                       ,double particle_mass 
                                       ,double total_mass  
                                       ,double sigma       
                                       ,double q  
                                       ,Utilities::RandomNumbers_NR &ran
                                       ){
  
  size_t Npoints = total_mass/particle_mass;
  PosType Rmax = (1+redshift)*total_mass*Grav*lightspeed*lightspeed/sigma/sigma/2;
  Point_3d<> point;
  double qq = sqrt(q);
  
  std::ofstream datafile;
  datafile.open(new_filename);
  
  datafile << "# nparticles " << Npoints << std::endl;
  datafile << "# mass " << particle_mass << std::endl;
  // create particles
  for(size_t i=0; i< Npoints ;++i){
    point[0] = ran.gauss();
    point[1] = ran.gauss();
    point[2] = ran.gauss();
    
    point *= Rmax*ran()/point.length();
    
    point[0] *= qq;
    point[1] /= qq;
    
    datafile << point[0] << " " << point[1] << " "
    << point[2] << " " << std::endl;
    
  }
  
  datafile.close();
}
 
  template<typename PType>
  LensHaloParticles<ParticleTypeSimple> LensHaloParticles<PType>::SIE(
           PosType redshift     
           ,double particle_mass 
           ,double total_mass  
           ,double sigma       
           ,double q  
           ,int Nneighbors
           ,COSMOLOGY &cosmo
           ,Utilities::RandomNumbers_NR &ran
                                         ){
    
    size_t Npoints = total_mass/particle_mass;
    PosType Rmax = total_mass*Grav*lightspeed*lightspeed/sigma/sigma/2;
    
    double qq = sqrt(q);
    
    std::cout << "making SIE LensHaloParticles..." << std::endl;
    std::cout << "# nparticles " << Npoints << std::endl;
    std::cout << "# mass " << particle_mass << std::endl;
 
    std::vector<ParticleTypeSimple> parts(Npoints);
    // create particles
    for(auto &p : parts){
      p[0] = ran.gauss();
      p[1] = ran.gauss();
      p[2] = ran.gauss();
      
      double s = Rmax*ran()/sqrt(p[0]*p[0] + p[1]*p[1] + p[2]*p[2] );
      p[0] *= s;
      p[1] *= s;
      p[2] *= s;
 
      p[0] *= qq;
      p[1] /= qq;
      
      p.Mass = particle_mass;
    }
    
    LensHaloParticles<ParticleTypeSimple> ::calculate_smoothing(Nneighbors,parts.data(),Npoints);
 
    return LensHaloParticles<ParticleTypeSimple>(parts,redshift
                            ,cosmo,Point_2d(0,0),false,0);
  }
 
template<typename PType>
LensHaloParticles<PType> & LensHaloParticles<PType>::operator=(LensHaloParticles<PType> &&h){
  if(this == &h) return *this;
  LensHalo::operator=(std::move(h));
  mcenter = h.mcenter;
  densest_point = h.densest_point;
  trash_collector =std::move(h.trash_collector);
  pp = h.pp;  // note: this depends on std:move keeping the pointer valid if it is constructed with the public constructor
  h.pp = nullptr;
  
  min_size = h.min_size;
  multimass = h.multimass;
  center = h.center;
  Npoints = h.Npoints;
  simfile = h.simfile;
  sizefile = h.sizefile;
  inv_area = h.inv_area;
  
  qtree = h.qtree;
  h.qtree = nullptr;
  
  return *this;
}
 
 
class MakeParticleLenses{
  
public:
  
  std::vector<LensHaloParticles<ParticleType<float> > *> halos;
  
  std::vector<size_t> getnp(){return nparticles;}
  
  std::vector<float> getmp(){return masses;}
  
  double sim_redshift(){return z_original;}
  
  MakeParticleLenses(const std::string &filename  
                     ,SimFileFormat format
                     ,int Nsmooth   
                     ,bool recenter 
                     //,bool compensate=false  /// if true a negative mass will be included so that  the region wil have zero massl
                     ,bool ignore_type_in_smoothing = false 
                     );
  
  MakeParticleLenses(const std::string &filename  
                     ,bool recenter 
                     //,bool compensate=false  /// if true a negative mass will be included so that  the region wil have zero massl
                    );
  
  ~MakeParticleLenses(){
    for(auto p : halos) delete p;
  }
  
 
  void Recenter(Point_3d<> x);
 
  void CreateHalos(const COSMOLOGY &cosmo,double redshift,double inv_area);
  
  void radialCut(Point_3d<> center,double radius);
  void cylindricalCut(Point_2d center,double radius);
 
  Point_3d<> getCenterOfMass() const{return cm;}
  
  Point_3d<> densest_particle() const;
 
  void getBoundingBox(Point_3d<> &Xmin,Point_3d<> &Xmax) const{
    Xmin = bbox_ll;
    Xmax = bbox_ur;
  }
  
  double getZoriginal(){return z_original;}
 
  std::vector<ParticleType<float> > data;
private:
  const std::string filename;
  int Nsmooth;
  //bool compensate;
  
  Point_3d<> bbox_ll;  // minumum coordinate values of particles
  Point_3d<> bbox_ur;  // maximim coordinate values of particles
  
  double z_original = -1;
  std::vector<size_t> nparticles;
  std::vector<float> masses;
  Point_3d<> cm;
 
  // write a glamB format file with all required particle data
  static void writeSizesB(const std::string &filename
                   ,std::vector<ParticleType<float> > &pv
                   ,int Nsmooth,std::vector<size_t> numbytype,double redshift){
    
    assert(numbytype.size() == 6);
    size_t ntot = pv.size();
    std::ofstream myfile(filename, std::ios::out | std::ios::binary);
    if(!myfile.write((char*)&Nsmooth,sizeof(int))){
      std::cerr << "Unable to write to file " << filename << std::endl;
      throw std::runtime_error("file writing error");
    }else{
      myfile.write((char*)&ntot,sizeof(size_t));
      myfile.write((char*)(numbytype.data()),sizeof(size_t)*6);
      myfile.write((char*)&redshift,sizeof(double));
      myfile.write((char*)(pv.data()),sizeof(ParticleType<float>)*ntot);
    }
  }
  
  // read a glamB format file
  static bool readSizesB(const std::string &filename
                   ,std::vector<ParticleType<float> > &pv
                  ,int &Nsmooth,std::vector<size_t> &numbytype,double &redshift){
    
    numbytype.resize(6);
    size_t ntot = pv.size();
    std::ifstream myfile(filename, std::ios::in | std::ios::binary);
    if(!myfile.read((char*)&Nsmooth,sizeof(int))){
      return false;
    }else{
      myfile.read((char*)&ntot,sizeof(size_t));
      myfile.read((char*)(numbytype.data()),sizeof(size_t)*6);
      myfile.read((char*)&redshift,sizeof(double));
      pv.resize(ntot);
      myfile.read((char*)(pv.data()),sizeof(ParticleType<float>)*ntot);
    }
    return true;
  }
  
  // Read particle from Gadget-2 format file
  bool readGadget2(bool ignore_type);
  
  // Reads particles from first 4 columns of csv file
  bool readCSV(int columns_used);
 
#ifdef ENABLE_HDF5
  bool readHDF5();
#endif
 
};
 
template<typename HType>
class LensHaloHalos : public LensHalo
{
public:
  
  LensHaloHalos(std::vector<HType> &pvector 
                    ,float redshift        
                    ,const COSMOLOGY& cosmo  
                    ,float inv_area
                    ,float my_theta_force=0.1
                    ,bool mu_periodic_buffer = false
                    ,bool verbose=false
  ):LensHalo(redshift,cosmo),inv_area(inv_area),theta_force(my_theta_force),periodic_buffer(mu_periodic_buffer)
  {
    std::swap(pvector,trash_collector);
    Nhalos = trash_collector.size();
    vpp.resize(Nhalos);
 
    for(size_t ii = 0 ; ii < Nhalos ; ++ii) vpp[ii] = &trash_collector[ii];
    set_up(redshift,cosmo,verbose);
  }
  ~LensHaloHalos();
  
  LensHaloHalos(LensHaloHalos &&h):LensHalo(std::move(h)){
    mcenter = h.mcenter;
    trash_collector =std::move(h.trash_collector);
    vpp = std::move(h.vpp);
    
    center = h.center;
    Nhalos = h.Nhalos;
    
    qtree = h.qtree;
    h.qtree = nullptr;
    
    inv_area = h.inv_area;
  }
  LensHaloHalos & operator=(LensHaloHalos &&h);
 
 
  void force_halo(double *alpha,KappaType *kappa,KappaType *gamma,KappaType *phi
                  ,double const *xcm
                  ,bool subtract_point=false,PosType screening = 1.0);
 
  size_t getN() const { return Nhalos; };
  
  Point_2d CenterOfMass(){return mcenter;}
  
protected:
  Point_2d mcenter;
  double inv_area;
  
  std::vector<HType *> vpp;
  std::vector<HType> trash_collector;
  
  Utilities::Geometry::SphericalPoint<> center;
  
  size_t Nhalos;
 
  float theta_force;
  bool periodic_buffer;
 
  TreeQuadHalos<HType> * qtree;
  
  void set_up(float redshift,const COSMOLOGY& cosmo,bool verbose);
};
 
template<typename HType>
void LensHaloHalos<HType>::set_up(
                                 float redshift        
                                 ,const COSMOLOGY& cosmo  
                                  ,bool verbose
){
 
  LensHalo::set_flag_elliptical(false);
  
  Rmax = 1.0e100;  // ????
  LensHalo::setRsize(Rmax);
 
  // convert from comoving to physical coordinates
  //PosType scale_factor = 1/(1+redshift);
  mcenter *= 0.0;
  PosType max_mass = 0.0,min_mass = HUGE_VALF,mass=0;
 
  for(HType &h : trash_collector){
    
    mcenter[0] += h[0]*h.get_mass();
    mcenter[1] += h[1]*h.get_mass();
    
    mass += h.get_mass();
    
    max_mass = (h.get_mass() > max_mass) ? h.get_mass() : max_mass;
    min_mass = (h.get_mass() < min_mass) ? h.get_mass() : min_mass;
  }
  LensHalo::setMass(mass);
  
  mcenter /= mass;
  
  if(verbose) std::cout << "   Particle mass range : " << min_mass << " to " << max_mass << "  ratio of : " << max_mass/min_mass << std::endl;
  
  qtree = new TreeQuadHalos<HType>(vpp.data(),Nhalos,inv_area,5,theta_force,periodic_buffer);
}
 
template<typename HType>
LensHaloHalos<HType>::~LensHaloHalos(){
  delete qtree;
}
 
template<typename HType>
void LensHaloHalos<HType>::force_halo(double *alpha,KappaType *kappa
                               ,KappaType *gamma,KappaType *phi
                                          ,double const *xcm
                                          ,bool subtract_point,PosType screening){
  qtree->force2D(xcm,alpha,kappa,gamma,phi);
 
  //   ?????
  alpha[0] *= -1;
  alpha[1] *= -1;
}
 
template<typename HType>
LensHaloHalos<HType> & LensHaloHalos<HType>::operator=(LensHaloHalos<HType> &&h){
  if(this == &h) return *this;
  LensHalo::operator=(std::move(h));
  mcenter = h.mcenter;
 
  trash_collector =std::move(h.trash_collector);
  vpp = std::move(h.vpp);  // note: this depends on std:move keeping the pointer valid if it is constructed with the public constructor
  
  center = h.center;
  Nhalos = h.Nhalos;
  
  qtree = h.qtree;
  h.qtree = nullptr;
  
  return *this;
}
 
#endif