Orders by minimum degree, permutes, and factors. Returns L in triplets, the permutation,
the log-determinant and the size of the final dense block.
Usage
sparse_chol(a, reorder = TRUE)
Arguments
- a
list i, j, x, n with the triplets of one triangle of the symmetric matrix
- reorder
FALSE factors in the natural order, so the tests can compare
Value
a list with L, the factor in triplets, perm, the permutation that was applied,
logdet, the log-determinant, and dense_block, the size of the final dense block.
Details
The ordering is minimum degree and not reverse Cuthill-McKee: RCM halves the fill-in but
puts the high-degree nodes FIRST, which is exactly where the closed form of the final
dense block cannot see them.
