NMath User's Guide

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Chapter 18. Using The Structured Sparse Matrix Classes (.NET, C#, CSharp, VB, Visual Basic, F#)

NMath provides a variety of functions that take the structured sparse matrix types described in Chapter 17 as arguments. Methods are provided either as member functions on the matrix classes, or as static methods on class MatrixFunctions.

As a general rule, NMath only provides functions that preserve the shape of the structured sparse matrices. In some cases, this means that functions provided for the general matrix classes are not provided for the structured sparse matrix classes. For example, NMath does not generally provide trigonometric and transcendental functions for structured sparse matrix types. Such functions may change unstored zero values to non-zero values, thus changing a structured sparse matrix type into a general matrix.

If you want to apply an arbitrary function to all elements of a structured sparse matrix, including unstored zero values, you can always convert the matrix to a general matrix first. A ToGeneralMatrix() method is provided for this purpose. Alternatively, to apply an arbitrary function only to stored values, you can apply the function to the underlying data vector. Both techniques are described in more detail in Section 18.7.

This chapter describes how to create and manipulate the NMath structured sparse matrix types.