A.1.6 Sparse Matrices in Oct-Files

There are three classes of sparse objects that are of interest to the user.

SparseMatrix

A double precision sparse matrix class

SparseComplexMatrix

A complex sparse matrix class

SparseBoolMatrix

A boolean sparse matrix class

All of these classes inherit from the Sparse<T> template class, and so all have similar capabilities and usage. The Sparse<T> class was based on Octave’s Array<T> class, and so users familiar with Octave’s Array classes will be comfortable with the use of the sparse classes.

The sparse classes will not be entirely described in this section, due to their similarity with the existing Array classes. However, there are a few differences due the different nature of sparse objects, and these will be described. First, although it is fundamentally possible to have N-dimensional sparse objects, the Octave sparse classes do not allow them at this time; All instances of the sparse classes must be 2-dimensional. This means that SparseMatrix is actually more similar to Octave’s Matrix class than its NDArray class.