Example DICOM2

This example demonstrates how to inherit from the DICOM example. For more information of the DICOM problem, see the documentation for the DICOM example

Introduction

This example demonstrates how to inherit from the DICOM example. For more information on the DICOM example, see the README in the DICOM example. In addition to demonstrating inheritance from DICOM, this example demonstrates method for memory savings, scoring into a sequential container instead of an associative container, accumulating the scoring with a statistics class instead of a simple floating point, and generic iteration over the variety of scoring container storage variants provided by Geant4

Configuration and Building

The DICOM example should be built and installed. By default, the CMake configuration for the DICOM example will install to the same directory as ${Geant4_DIR}.

When configurating this example, provide DICOM_DIR=<path-to-cmake-configuration>, e.g.

$ cmake -DGeant4_DIR=/usr/local/lib/Geant4-10.5.0 -DDICOM_DIR=/usr/local/lib/Geant4-10.5.0 <path-to-source>

This example will enable DCMTK and/or DICOM_HEAD based on the configuration set when the DICOM example was installed. The files "Data.dat.old" and "Data.dat.new" follow the same pattern of being copied to "Data.dat" in the binary directory that is detailed out in Section 4 of the DICOM README.

Class Overview

• Dicom2Run:
  • How to save memory with G4VTHitsVector instead of G4THitsMap
  • How to implement G4VTHitsVector with objects instead of pointers (saving more memory)
  • How to use G4StatAnalysis within G4VTHitsVector (or G4VTHitsMap) to obtain per-voxel statistics
    • G4StatAnalysis provides standard deviation, mean, variance, relative error, FOM, r2int, r2eff, coefficient of variant, and efficiency in a class that consumes significantly less memory than G4ConvergenceTester
  • Implements scoring accumulation over the course of a run in G4VTHitsVector<G4StatAnalysis, std::vector<G4StatAnalysis>> Dicom2RunVector
    • The first template parameter is the type of the data (i.e. double, G4StatAnalysis, etc.) and the second template parameter is the underlying storage type – by specifying std::vector<G4StatAnalysis>, we override the default storage format of std::vector<G4StatAnalysis*> which results in memory savings
• Dicom2RunAction:
  • Overloads EndOfRunAction(const G4Run*) to print out the same quantities as DICOM but with the G4StatAnalysis class
  • Demonstrates generic iteration of hits containers
    • The new iteration scheme over hits containers works regardless of whether the underlying storage type is a map, multimap, unordered_map, unordered_multimap, vector, or deque and regardless of whether the data type stored in the sequential container types (vector and deque) are an object or or a pointer to an object
• Dicom2PrimaryGeneratorAction:
  • Minor variation of DicomPrimaryGeneratorAction that randomizes the initial direction of the particle
• Dicom2ActionInitialization:
  • In addition Dicom2RunAction and Dicom2PrimaryGeneratorAction, this class instantiates DicomEventAction