Sparse matrices

Sparse matrices are special matrices that have many zero elements. These zero elements are not stored in memory, which can save a lot of space, and they are not used in calculations, which can save a lot of compute time. On the other hand, the algorithms for sparse matrices are more complex and slower than for dense matrices, so it is important to know that the matrix is actually sparse to use this type.

The Sparse class is implemented in the matpack package. The implementation is just a wrap of Eigen::SparseMatrix for floating-point data. The class supports basic operations like scaling, addition, subtraction, as well as the linear algebra operations of matrix-matrix and matrix-vector multiplication.

This class is accessible through the python interface via Sparse.

Like Band matrices, this is a very simple class that has very specialized use cases. It is not recommended using this class for general purpose linear algebra, but it can be very useful for specific problems.

Relevant files

The relevant files for the data holding core matpack types are:

• matpack/matpack_sparse.h - the Sparse class.