The Harwell-Boeing Sparse Matrix Collection is a set of standard test
matrices arising from problems in linear systems, least squares, and eigenvalue
calculations from a wide variety of scientific and engineering disciplines. The
problems range from small matrices, used as counter-examples to hypotheses in
sparse matrix research, to large test cases arising in applications. The
collection was originally developed by Iain Duff, Roger
Grimes, and John Lewis.

Matrices in the collection can also be downloaded by anonymous ftp from