void AliPMDAlObjRnd(Float_t max_trans=1.0, Float_t max_rot=0.1)
{
  // Macro to randomly displace the 4 sectors of the PMD
  // in each plane. Each sector (to be misaligned) 
  // of PMD houses the following :
  // (a) 6 modules of preshower plane
  // (b) 6 modules of veto plane
  // (c) The FEE boards on back plane of each module
  // (d) 6 modules of convertor plates
  // The clustering is done module-wise
  // The actual amount displacement will be provided
  // by the survey data and has to be converted into
  // displacement in x,y,z,theta, phi and psi 
  
  
  // Now specify the path of the module to be misaligned
  // as followed in the PMD geant
  
  /*
     _____________
    |    |        |
    | 1  |   3    |
    |    |________|
    |____|___|    |
    |        | 2  |
    |   4    |    |
    |________|____|
    
    // Misalignment Matrix is expected to be
    // same for sectors 1 and 4 
    // and for the sectors 2 and 3
    // As these will be mounted on the same
    // Steel plate 
 */
  
  TString path;
  const char *Sector1="/ALIC_1/EPM1_1"; 
  const char *Sector2="/ALIC_1/EPM2_1"; 
  const char *Sector3="/ALIC_1/EPM3_1"; 
  const char *Sector4="/ALIC_1/EPM4_1"; 
  
  
  //Sectors 1 and 4
  Double_t dx14, dy14, dz14;          // Misalignment in X,Y and Z
  Double_t dpsi14, dtheta14, dphi14; //  Angular displacements
  //Sectors 2 and 3
  Double_t dx23, dy23, dz23;          // Misalignment in X,Y and Z
  Double_t dpsi23, dtheta23, dphi23; //  Angular displacements
  
  
  
  // At present give some random shifts
  // generated by random numbers
  // max_trans : Maximun shifts in X,Y,Z  in centimeters
  // max_rot   : Maximum shifts in angles in degrees
  // Double_t max_trans, max_rot;
  
  
  TRandom *rnd   = new TRandom(4357);
  
  // For sectors 1 and 4
  // Translation displacement
  dx14     = (rnd->Uniform()-0.5)*max_trans;
  dy14     = (rnd->Uniform()-0.5)*max_trans;
  dz14     = (rnd->Uniform()-0.5)*max_trans;
  //Rotation angles
  dpsi14   = (rnd->Uniform()-0.5)*max_rot;
  dtheta14 = (rnd->Uniform()-0.5)*max_rot;
  dphi14   = (rnd->Uniform()-0.5)*max_rot;
  
  // For sectors 2 and 3
  // Translation displacement
  dx23     = (rnd->Uniform()-0.5)*max_trans;
  dy23     = (rnd->Uniform()-0.5)*max_trans;
  dz23     = (rnd->Uniform()-0.5)*max_trans;
  //Rotation angles
  dpsi23   = (rnd->Uniform()-0.5)*max_rot;
  dtheta23 = (rnd->Uniform()-0.5)*max_rot;
  dphi23   = (rnd->Uniform()-0.5)*max_rot;
  
  
  //Create a TClonesArray of Align Object to store displacement Angles
  TClonesArray *array = new TClonesArray("AliAlignObjParams",10000);
  TClonesArray &alobj = *array;
  
  // Create a File to store the alignment data
  // the translations and rotations
  
  TFile f("PMD_rnd_alobj.root","RECREATE");
  if(!f) {cerr<<"cannot open file for output\n";}
  
  AliAlignObjParams o;
  
  UShort_t iIndex=0;
//   AliGeomManager::ELayerID iLayer = AliGeomManager::kTOF;

//   UShort_t dvoluid = AliGeomManager::LayerToVolUID(iLayer,iIndex); //dummy volume identity 

  new(alobj[0]) AliAlignObjParams(Sector1, iIndex, dx14, dy14, dz14, dpsi14, dtheta14, dphi14);
  new(alobj[1]) AliAlignObjParams(Sector2, iIndex, dx14, dy14, dz14, dpsi14, dtheta14, dphi14);
  new(alobj[2]) AliAlignObjParams(Sector3, iIndex, dx23, dy23, dz23, dpsi23, dtheta23, dphi23);
  new(alobj[3]) AliAlignObjParams(Sector4, iIndex, dx23, dy23, dz23, dpsi23, dtheta23, dphi23);
  
  // This part needs to be understood
  f.cd();
  f.WriteObject(array,"PMDAlignObjs","kSingleKey");
  f.Close();
  array->Delete();
}