test.c

// CPP program to demonstrate multithreading
// using three different callables.
#include <future>
#include <iostream>
#include <thread>
#include <itpp/itbase.h>
#include <itpp/itcomm.h>
#include "my_lib.h"
#include <math.h>
#include "bp_decoder.h"
#include<algorithm> // for std::for_each
using namespace std;
using namespace itpp;


// A dummy function
void foo(int Z)
{
  for (int i = 0; i < Z; i++) {
            cout << "Thread using function"
	      " pointer as callable\n";
  }
}

// A callable object
class thread_obj {
 public:
  void operator()(int x)
  {
    for (int i = 0; i < x; i++)
                  cout << "Thread using function"
		    " object as  callable\n";
  }
};

//cannot compile unless it is in main()
/*
int thread_test()
{
      cout << "Threads 1 and 2 and 3 "
	"operating independently" << endl;

      // This thread is launched by using
      // function pointer as callable
      thread th1(foo, 3);

      // This thread is launched by using
      // function object as callable
      thread th2(thread_obj(), 3);

      // Define a Lambda Expression
      auto f = [](int x) {
	for (int i = 0; i < x; i++)
	              cout << "Thread using lambda"
			" expression as callable\n";
      };

      // This thread is launched by using
      // lamda expression as callable
      thread th3(f, 3);

      pthread_join(th1, NULL);
      pthread_join(th2, NULL);
	
      // Wait for the threads to finish
      // Wait for thread t1 to finish
      //th1.join();

      // Wait for thread t2 to finish
      //th2.join();

      // Wait for thread t3 to finish
      th3.join();

      return 0;
} 
*/

/*
int bp_test(){
  cout<<"Test the bp_syndrome_llr function"<<endl;
  //choose code

  //toric code
  int size=25;
  string stabilizer_folder="data/toric/stabilizer";
  string filename_H = stabilizer_folder + "/toric_S_z_size_" + to_string(size) + ".mm";
  //GF2mat H =MM_to_GF2mat(filename_H);

   GF2mat H = get_check(2,35); // repetition code


  
  //  GF2mat H = get_check(2,7);
  //  H = H.get_submatrix(0,0,2,6);
  //  cout<<"parity check H = \n"<<H<<endl;
  GF2matPrint(H);
  bvec error = zeros_b(H.cols());
  switch ( 2 ) {
  case 0:
    error.set(0,1);break;
  case 1:
    error.set(1,1);
    //error.set(3,1);
    error.set(0,1);
    break;
  case 11:
    error.set(63,1);
    //error.set(3,1);
    error.set(56,1);
    break;
  case 12:
    error.set(49,1);
    //error.set(3,1);
    error.set(56,1);
    break;
  case 13:
    error.set(35,1);
    //error.set(3,1);
    error.set(36,1);
    break;
  case 2:
    error.set(0,1);
    error.set(1,1);
    error.set(2,1);
    error.set(3,1);
    //  error.set(4,1);
    error.set(5,1);
    error.set(6,1);
    error.set(7,1);
    error.set(11,1);
    break;
  case 3:
    for (int i =0; i<10; i++) error.set(2*i,1);break;

  }
  error=find_error(error,H);
      
  cout<<"input error ="<<error<<endl;
  
  bvec syndrome = (H*error);
  cout<<"syndrome = "<<syndrome<<endl;
  vec LLRin(H.cols());
  double p =0.01;
  double LLR=log( (1-p)/p);
  LLRin.ones();
  LLRin = LLRin*LLR;    
  vec LLRout(LLRin);//default, zero syndrome give zero error
  //LLRout.zeros();
  cout<<"LLRin  = "<< LLRin<<endl;
  //  cout<<"LLRout = "<< LLRout<<endl;
  int exit_iteration = 49;
  int iteration = bp_syndrome_llr(H,syndrome,LLRin, LLRout, exit_iteration);
  cout<<" iteration = "<<iteration <<endl;
  //  cout<<" LLRout = "<<LLRout<<endl;
  bvec bits_out = LLRout < 0;
  //  cout<<"bits_out = "<<bits_out<<endl;
  draw_toric_x_error(bits_out,"bits_out");
  //cout<<"error    = "<<error<<endl;
  draw_toric_x_error(error,"error");
  cout<<"syndrome = "<<syndrome<<endl;
  bvec error_residue = error + bits_out;
  bvec syndrome_residue = H*error_residue;
  //  cout<<"error_residue = "<< error_residue <<endl;
  draw_toric_x_error(error_residue,"error_residue");
  cout<<"syndrome_residue = "<< syndrome_residue <<endl;
  return 0;
}
*/

void bp_decoder_class_test(){
  cout<<"Test the bp_syndrome_llr function"<<endl;
  //choose code

  //toric code
  int size=25;
  string stabilizer_folder="data/toric/stabilizer";
  string filename_H = stabilizer_folder + "/toric_S_z_size_" + to_string(size) + ".mm";
  //GF2mat H =MM_to_GF2mat(filename_H);

   GF2mat H = get_check(2,35); // repetition code


  
  //  GF2mat H = get_check(2,7);
  //  H = H.get_submatrix(0,0,2,6);
  //  cout<<"parity check H = \n"<<H<<endl;
  GF2matPrint(H);
  bvec error = zeros_b(H.cols());
  switch ( 2 ) {
  case 0:
    error.set(0,1);break;
  case 1:
    error.set(1,1);
    //error.set(3,1);
    error.set(0,1);
    break;
  case 11:
    error.set(63,1);
    //error.set(3,1);
    error.set(56,1);
    break;
  case 12:
    error.set(49,1);
    //error.set(3,1);
    error.set(56,1);
    break;
  case 13:
    error.set(35,1);
    //error.set(3,1);
    error.set(36,1);
    break;
  case 2:
    error.set(0,1);
    error.set(1,1);
    error.set(2,1);
    error.set(3,1);
    //  error.set(4,1);
    error.set(5,1);
    error.set(6,1);
    error.set(7,1);
    error.set(11,1);
    break;
  case 3:
    for (int i =0; i<10; i++) error.set(2*i,1);break;

  }
  error=find_error(error,H);
      
  cout<<"input error ="<<error<<endl;
  
  bvec syndrome = (H*error);
  cout<<"syndrome = "<<syndrome<<endl;
  vec LLRin(H.cols());
  double p =0.01;
  double LLR=log( (1-p)/p);
  LLRin.ones();
  LLRin = LLRin*LLR;    
  vec LLRout(LLRin);//default, zero syndrome give zero error
  //LLRout.zeros();
  cout<<"LLRin  = "<< LLRin<<endl;
  //  cout<<"LLRout = "<< LLRout<<endl;
  int exit_iteration = 49;

  //set up class BP_Decoder;
  BP_Decoder bp_decoder;
  bp_decoder.init(H);
  bp_decoder.set_exit_iteration(exit_iteration);
  bp_decoder.set_decode_mode(2);
  bp_decoder.print_info();
  int iteration = bp_decoder.bp_syndrome_llr(syndrome, LLRin,LLRout);
  //  int iteration = bp_syndrome_llr(H,syndrome,LLRin, LLRout, exit_iteration);
  cout<<" iteration = "<<iteration <<endl;
  //  cout<<" LLRout = "<<LLRout<<endl;
  bvec bits_out = LLRout < 0;
  //  cout<<"bits_out = "<<bits_out<<endl;
  draw_toric_x_error(bits_out,"bits_out");
  //cout<<"error    = "<<error<<endl;
  draw_toric_x_error(error,"error");
  cout<<"syndrome = "<<syndrome<<endl;
  bvec error_residue = error + bits_out;
  bvec syndrome_residue = H*error_residue;
  //  cout<<"error_residue = "<< error_residue <<endl;
  draw_toric_x_error(error_residue,"error_residue");
  cout<<"syndrome_residue = "<< syndrome_residue <<endl;
  return;
}

void switch_test(int a){
  switch (a) {
  case 1:
  case 2:
    std::cout<<"1 2"<<std::endl;
    break;
  case 3:
  case 4:
    std::cout<<"3 4 "<<std::endl;
    break;
  default:
    std::cout<<"none"<<std::endl;
    break;
  }
  return;
}

int main(){
  itpp::Real_Timer timer;
  timer.tic();
  //thread_test();
  //bp_test();
  //bp_decoder_class_test();

  switch_test(3);
    switch_test(4);
    switch_test(5);

    std::vector<std::string> foo;
    std::for_each(
		  std::execution::par_unseq,
		  foo.begin(),
		  foo.end(),
		  [](auto&& item)
		  {
		    //do stuff with item
		    std::cout<<"hello"<<std::endl;
		  });
    
  //  double t = timer.toc();
  //  std::cout<<t<<endl;
    
  timer.toc_print();
}