mgmres, a FORTRAN90 code which applies the restarted Generalized Minimum Residual (GMRES) algorithm to solve a sparse linear system, using compressed rows storage (CRS) or sparse triplet (ST) format, by Lili Ju.
One matrix format used is the sparse triplet (ST) format, which simply stores NZ_NUM, the number of nonzeros, and stores the K-th nonzero matrix entry as
Another matrix format used is the compressed row storage (CRS) format, which is similar to the sparse triplet format except that the vector of row indices is compressed to a vector of length N+1 which points to the beginning of the set of entries for each row.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
mgmres is available in a C version and a C++ version and a FORTRAN90 version and a MATLAB version.
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SPARSEKIT, a FORTRAN90 code which implements operations on sparse matrices, including conversion between various formats.
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C version by Lili Ju, Mathematics Department, University of South Carolina; FORTRAN90 version by John Burkardt.