sparseLM is a software package for efficiently solving arbitrarily sparse non-linear least squares problems. It offers a generic implementation of the Levenberg - Marquardt optimization algorithm on top of a variety of sparse direct solvers, thus being applicable to problems with arbitrary sparseness. sparseLM accepts sparse Jacobians encoded in either compressed row storage (CRS) or compressed column storage (CCS, aka Harwell-Boeing) format. It is also possible to supply it just with the Jacobian's sparsity pattern and have its values be numerically approximated using finite differences, or even instruct it to attempt the automatic detection of the sparsity pattern corresponding to the Jacobian of the function to be minimized. Note that for dense non-linear least squares problems, project levmar is more appropriate.
