We have decided to discontinue the publication of preprints on our preprint server as of 1 March 2024. The publication culture within mathematics has changed so much due to the rise of repositories such as ArXiV (www.arxiv.org) that we are encouraging all institute members to make their preprints available there. An institute's repository in its previous form is, therefore, unnecessary. The preprints published to date will remain available here, but we will not add any new preprints here.
Technical Report
10/2008
HLIBpro C Language Interface
Ronald Kriemann
Abstract
HLIBpro is a software library implementing hierarchical matrices or H-matrices for short. This type of matrices provides a technique to represent various full matrices in a data-sparse format and furthermore, allows usual matrix arithmetic, e.g. matrix-vector multiplication, matrix multiplication and inversion, with almost linear complexity. Examples of matrices, which can be represented by H-matrices stem from the area of partial differential or integral equations.
Beside the standard arithmetic mentioned above, HLIBpro also provides additional algorithms for decomposing matrices, e.g. LU-factorisation and for solving linear equation systems with various direct or iterative methods. Furthermore, it contains methods for directly converting a dense operator into an H-matrix without constructing the corresponding dense matrix.
This manual describes the interface to the HLIBpro library from the C programming language.