DESCRIPTION=" mdds provides the following data structures: Segment tree: A balanced-binary-tree based data structure efficient for detecting all intervals (or segments) that contain a given point. Flat segment tree: A variant of segment tree that is designed to store a collection of non-overlapping segments. Rectangle set: Stores 2-dimensional rectangles and provides an efficient way to query all rectangles that contain a given point in 2-dimensional space. Point quad tree: Stores 2-dimensional points and provides an efficient way to query all points within specified rectangular region. Multi-type vector: Storage of unspecified number of types in a single logical array such that contiguous elements of identical type are stored in contiguous segment in memory. Multi-type matrix: A matrix structure that allows storage of four different element types: numeric, string, boolean and empty."
