RB is a data directory which contains examples of the RB or Rutherford Boeing Sparse Matrix File Format, which is used to store a sparse matrix in a file.
Since most of the matrix is presumably zero, a great deal of storage can be saved if only the nonzero entries are stored. The file format offers a choice of two suitable representations for the nonzero data: a compressed column format, or a format suitable for finite element matrices.
The two representations, compressed column or finite element, may then be stored in a file using either the Rutherford Boeing format (RB) or a Matrix Market format (MM).
Often, a sparse matrix has associated information, such as eigenvectors, or special right hand sides. The RB format offers a supplementary format to store such information in files in a standardized way, so that this information can be easily associated with the sparse matrix and retrieved as needed. Note that the Harwell-Boeing format, a predecessor to the RB format, required all supplementary information to be included in the same file as that storing the sparse matrix.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
HB, a data directory which contains examples of HB files, the Harwell Boeing sparse matrix file format;
MM, a data directory which contains examples of MM files, the Matrix Market Sparse Matrix File Format;
EXAMPLE1 is a 5x5 real general matrix.
EXAMPLE2 is a 10x10 square symmetric matrix in elemental form. The matrix is formed as the sum of 6 symmetric 3x3 matrices and one symmetric 4x4 matrix. Because symmetry is specified, only the diagonal and lower triangle of these matrices are to be supplied.
EXAMPLE3 is a 5x5 square matrix in elemental form. The matrix is not symmetric, but it is structurally symmetric. The matrix is formed as the sum of 4 square finite element matrices.
EXAMPLE4 is a 4x5 small rectangular matrix in elemental form. The matrix is formed as the sum of 3 rectangular finite element matrices.
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