The test matrices are download from the MatrixMarket
(`http://math.nist.gov/MatrixMarket`).
These are square matrices of size ranging from 2534
to 94069. These matrices are in the MatrixMarket coordinate format.
For example, for the following sparse matrix with 8
nonzero entries,

(2) |

%%MatrixMarket matrix coordinate real general 5 5 8 1 1 1.000e+00 2 2 1.050e+01 3 3 1.500e-02 1 4 6.000e+00 4 2 2.505e+02 4 4 -2.800e+02 4 5 3.332e+01 5 5 1.200e+01

Because matrices from MatrixMarket may contain sparse patterns without any entry values, for simplicity all matrix files have been converted to a form with only the sparse pattern. Thus for example the above matrix will be in the form

5 5 8 1 1 2 2 3 3 1 4 4 2 4 4 4 5 5 5All the matrix entries are set to one after reading in the sparse pattern.