Harwell-Boeing matrix format.
Used for exchanging and storing sparse matrices.
Plain text format.
File format of the Harwell-Boeing collection of standard test matrices.
The three-letter file extension encodes matrix properties that are also represented in the file.
The first letter of the file extension encodes the data type: "r" (real), "c" (complex), or "p" (pattern).
The second letter denotes the symmetry property: "s" (symmetric), "u" (unsymmetric), "h" (Hermitian), "z" (skew-symmetric), or "r" (rectangular).
The third letter of the file extension is either "a" (assembled) or "e" (elemental unassembled).
Stores matrices in a sparse representation.
Developed in 1992 by Iain Duff, Roger Grimes, and John Lewis.