Editing Adjusting Variables at Run-Time (section)

==Input Files==

'''Example:''' Initialization File 

 #X-length of both scintillators (in cm)
 scintX 30.5
 #Y-length of both scintillators (in cm)
 scintY 17.0
 #Z-length of both scintillators (in cm)
 scintZ 1.0
 #height(POSITION) of bottom scintillator (in cm)
 bottomScintPos -30.0
 #height(POSITION) of top scintillator (in cm)
 topScintPos 30
 #thickness of the Lead layer (in cm)
 blockThickness 15.0
 #the material the block will be made of (must be a valid G4Material name)
 blockMaterial G4_Pb
 #name of the output file(ONLY THE BASE NAME, THICKNIESS WILL BE ADDED AS A SUFFIX IN THE PROGRAM)
 #outFileBase S1_thickness_
 outFileBase S1_uncert_
 #the run number (for finding an uncertainty in positron count)
 runNum 10

As seen above, the initialization file is essentially a list of all variables in the program that may be necessary to change between runs. The benefit to using this type of file is that it can be changed without having to recompile the program. Obviously it is crucial to know what type these variable should be, what units the number should be in if applicable, and what order these variables should be in. The hash-tagged lines are comments, and should be used gratuitously if some other person may end up using the program so the requirements of the input file are clear.

Input files get read at run-time by the variables class via the main file. In other words, the main calls a read file function of the variables class that then reads and saves the appropriate variables. Typically this is the first, or one of the first, actions to occurs in the main. A quick example of the line in the main is provided below, and a more robust explanation of the variables class is provided in another section farther below.

 int main(int argc,char** argv)
 {
      //The first object to load should be the variables, since they are read externally
      //Create a variables object to read and store the variables
      Variables = new S1Variables();
 
      //Insert the input file here, ours is called S1.ini
      G4String dataname = "S1.ini";
 
      //call the function to read the data from the file
      Variables->loadFromFile(dataname);