Utilities.h

#include <fstream>

using namespace std;

//__________________________________________________________________________________________________________________________
bool does_file_exist(const char *fileName)
{
    // A very simple function to test if a file exists
    // Main use is to ensure that the output file is not overwriting an existing file.
    
    return static_cast<bool>(std::ifstream(fileName));
}




//__________________________________________________________________________________________________________________________
int GetVolumneId(int ixx, int iyy, int ixx_MAX)
{
    return ixx + (iyy - 1) * ixx_MAX;
}




//__________________________________________________________________________________________________________________________
std::vector<int> GetPPtFromVolumeId(int volumeID, int ixx_MAX, bool debug = false)
{
    int ipt = (int)volumeID/(int)ixx_MAX + 1;
    int ipp = volumeID % ixx_MAX;
    
    if (ipp == 0)
    {
        ipp = ixx_MAX;
        ipt = ipt - 1;
    }
    
    if (debug == true) cerr<<"Verify (ipp, ipt) = "<<ipp<<", "<<ipt<<endl;
    
    std::vector<int> ipp_ipt = {ipp, ipt};
    return ipp_ipt;
}




//________________________________________________________________________________________________________
void printVector(const vector<int> &v) 
{
   for (int x : v) 
   {
       std::cout << x << ", ";
   }
   std::cout<<endl;
}




//________________________________________________________________________________________________________
bool IsInRange(const double &p, const double &v1, const double &v2)
{
    
    return v1 <= v2            // <- v1 and v2 are compared only once
        ? v1 <= p && p <= v2   // check if the ordering is v1, p, v2.
        : v2 <= p && p <= v1;  // check if the ordering is v2, p, v1.
}

//________________________________________________________________________________________________________
bool IsCleanDeuteronCandidate(const double &momentum, const double &pT, const double &massSQ, const double &dEdx)
{
    if (pT > 1.5)
        return false;
    
    if (momentum >= 12.0 || momentum <= 4.0)
        return false;
    
    const double massSQD = 3.52;
    const double massSQD_min = 0.95*massSQD;
    const double massSQD_max = 1.05*massSQD;
    if (massSQ >= massSQD_max || massSQ <= massSQD_min)
        return false;
    
    const double massD = 1.8756;
    double dEdx_deuteronBB = BetheBlochAntoniMod(momentum/massD);
    double dEdx_deuteronBB_min = 0.95*dEdx_deuteronBB;
    double dEdx_deuteronBB_max = 1.05*dEdx_deuteronBB;
    if (dEdx >= dEdx_deuteronBB_max || dEdx <= dEdx_deuteronBB_min)
        return false;
    else
        return true;
}