**Chapter
17. **** Structured Sparse Matrix Types** (.NET, C#, CSharp, VB, Visual Basic, F#)

**NMath** provides
a wide variety of structured sparse matrix types, including triangular,
symmetric, Hermitian, banded, tridiagonal, symmetric banded, and Hermitian
banded.

A *sparse matrix*
is a matrix with only a small number of nonzero elements. A *structured* *sparse matrix* is one in which the zero elements
(or elements contributing no new information) are distributed according
to some pattern. By exploiting this pattern, structured sparse matrices
can be manipulated more efficiently than general matrices, since all
of the elements do not need to be stored.

This chapter describes the **NMath**
structured sparse matrix types, and the storage schemes they use. See
Chapter 19
for general sparse matrix classes.