CTDR_Field

 Constructor for the CTDR_Field 
 We retrieve 3 TTree from a file. These data tree contain data of the CTDR_Field inside a logical pixel of
 our detector. The data are obtained from a finite-emelent analysis software, COMSOL multiphysics, and
 we retreive an array of 100*100*100 for nodes inside the model at constant distance. Each data point
 is assigned a unique ID calculated from its position. It allow us to get the memory adress of a CTDR_Field value
 by calculating the ID associated to the position where we need the value. We then retreive the CTDR_Field
 value from the tree using this unique ID pointing to its adress in the tree's memory 
 The data trees are created one time , prior to simulation, using Treereader.c ROOT script .
 This allow to modify the script to use CTDR_Field Data from various sources without touching this code. 
 The Storage of the data in .root files allow to get in memory large amount of data, compressed with
 an efficient method that allow a fast acces to data in the tree. S 
 parameters: (reference to the ROOT file, number of division in X (100), in Y, in Z, size of the model
 in X,Y,Z)

Data access function for the CTDR_Field components

Data access function for the CTDR_Field components

Data access function for the CTDR_Field components

This function Put in the public variable Ex,Ey,Ez, the CTDR_Field value for the point xx,yy,zz

 This function calculate the linear 3D interpolation of the Field at x,y,z, 
   1. We calculate the ID of the 8 surrounding points to (x,y,z)
   2. We get the Field value at he adress corresponding to these ID. 
   3  We compute the interpolation and put the interpolated values in Ex,Ey,Ez  

Access method for the Model depth in z