ABACUS/src/EXECS/LiebLin_Moses_tester.cc

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

This software is part of J.-S. Caux's ABACUS library.

Copyright (c) J.-S. Caux.

-----------------------------------------------------------

File:  LiebLin_DSF_tester.cc

Purpose:  allows for Ix2 manipulations (user-prompted) for LiebLin gas

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

#include "ABACUS.h"

using namespace std;
using namespace ABACUS;


int main(int argc, char* argv[])
{

  if (argc != 8) { // provide some info

    cout << endl << "Welcome to ABACUS\t(copyright J.-S. Caux)." << endl;
    cout << endl << "Usage of LiebLin_DSF_tester executable: " << endl;
    cout << endl << "Provide the following arguments:" << endl << endl;
    cout << "char whichDSF \t\t Which structure factor should be calculated ?  Options are:  "
      "d for rho rho, g for psi psi{dagger}, o for psi{dagger} psi" << endl;
    cout << "DP c_int \t\t Value of the interaction parameter:  use positive real values only" << endl;
    cout << "DP L \t\t\t Length of the system:  use positive real values only" << endl;
    cout << "int N \t\t\t Number of particles:  use positive integer values only" << endl;
    cout << "int Nl \t\t\t Number of particles in left Fermi sea (Nr is then N - Nl)" << endl;
    cout << "int DIl \t\t shift of left  sea as compared to its ground state position" << endl;
    cout << "int DIr \t\t shift of right sea as compared to its ground state position" << endl;
  }

  else { // (argc == 6), correct nr of arguments
    char whichDSF = *argv[1];
    DP c_int = atof(argv[2]);
    DP L = atof(argv[3]);
    int N = atoi(argv[4]);
    int Nl = atoi(argv[5]);
    int DIl = atoi(argv[6]);
    int DIr = atoi(argv[7]);

    if (whichDSF != 'd') ABACUSerror("Other options not implemented yet in LiebLin_Moses_tester");

    // Define the Moses state:
    LiebLin_Bethe_State MosesState (c_int, L, N);

    // Split the sea:
    for (int i = 0; i < Nl; ++i) MosesState.Ix2[i] -= 2 * DIl;
    for (int i = Nl; i < N; ++i) MosesState.Ix2[i] += 2 * DIr;

    MosesState.Compute_All (true);

    LiebLin_Bethe_State estate = MosesState;
    cout << MosesState;

    int Ix2old, Ix2new;
    int again = 0;
    do {
      cout << "Substitute Ix2:  which for which ?" << endl;
      cin >> Ix2old >> Ix2new;
      for (int i = 0; i < estate.N; ++i) if (estate.Ix2[i] == Ix2old) estate.Ix2[i] = Ix2new;
      estate.Compute_All(false);
      cout << estate;
      cout << setprecision(16) << "omega = " << estate.E - MosesState.E << "\t"
	   << exp(real(ln_Density_ME(MosesState, estate))) << endl;
      cout << "Another try ? (0 == no)" << endl;
      cin >> again;
    } while (again != 0);

  }

  return(0);
}