1. Add Solver::Options::use_mixed_precision_solves,
and Solver::Options::max_num_refinement_iterations.
2. Make SparseCholesky::Create return a unique_ptr.
3. SparseCholesky::Create now takes LinearSolver::Options
as an argument.
4. IterativeRefiner's constructor does not require num_cols
as an argument.
5. SparseNormalCholeskySolver now uses a separate rhs vector.
This basic implementation results in a 10% reduction in solver time
and 30% reduction in linear solver memory usage.
Change-Id: I6830f32cae2febf082d2733262eb2c9f0482b0ea
The key idea being, use some subset of the rows of the Jacobian
as the preconditioner.
This CL only implements the preconditioner assuming that the row
selection has already been done. How the rows are selected will be
left to the user based on their knowledge of the problem.
A follow up CL will hook this preconditioner into the rest of the
solver.
Change-Id: I3e18dc57811116534e9ddf35d7b154bcce496d3b