This document describes a contribution to the Insight Toolkit intended to support the analysis of the principal components of data sets, optionally point data associated with the vertices of a mesh.
This paper is accompanied with the source code, input data, parameters and output data that we used for validating the implementation described in this paper. This adheres to the fundamental principle that scientific publications must facilitate reproducibility of the reported results.

Principal Components Analysis of Scalar, Vector, and Mesh Vertex Data

The Insight Segmentation and Registration Toolkit (ITK) previously provided a framework for parsing Extensible Markup Language (XML) documents using the Simple API for XML (SAX) framework. While this programming model is memory efficient, it places most of the implementation burden on the user. We provide an implementation of the Document Object Model (DOM) framework for parsing XML documents. Using this model, user code is greatly simplified, shifting most of the implementation burden from the user to the framework. 
The provided implementation consists of two tiers. The lower level tier provides functionality for parsing XML documents and loading the tree structure into memory. It then allows the user to query and retrieve specific entries. The upper tier uses this functionality to provide an interface for mimicking a serialization and de-serialization mechanism for ITK objects. The implementation described in this document was incorporated into ITK as part of release 4.2.

Document Object Model based XML Handling in ITK

In the medical simulation world the use of isosurfaces is a common action, as the information from some sources, e.g. CTs, is very well defined, and the isosurface can be easily set. Additionally, in any simulator shadows are a necessary addition to increase the users immersion as well as its depth perception. Unfortunately, the Visualization Toolkit does not offer these features, and so in this paper a modified vtkGPUVolumeRayCastMapper is presented. This modified version allows volumetric isosurface rendering as well as receiving shadows from polygons using the usual pipeline. 