1. Remove constant_sparsity from LinearSolver::Options. It introduces
unnecessarily complexity in the structure of linear solvers and preconditioners.
This is the first step towards cleaning up the Preconditioner interface.
2. Minor tweaks and cleanups to the various linear solvers.
diff --git a/internal/ceres/linear_solver.h b/internal/ceres/linear_solver.h
index 5860ecc..299a541 100644
--- a/internal/ceres/linear_solver.h
+++ b/internal/ceres/linear_solver.h
@@ -55,10 +55,11 @@
// Ax = b
//
// It is expected that a single instance of a LinearSolver object
-// maybe used multiple times for solving different linear
-// systems. This allows them to cache and reuse information across
-// solves if for example the sparsity of the linear system remains
-// constant.
+// maybe used multiple times for solving multiple linear systems with
+// the same sparsity structure. This allows them to cache and reuse
+// information across solves. This means that calling Solve on the
+// same LinearSolver instance with two different linear systems will
+// result in undefined behaviour.
//
// Subclasses of LinearSolver use two structs to configure themselves.
// The Options struct configures the LinearSolver object for its
@@ -73,7 +74,6 @@
min_num_iterations(1),
max_num_iterations(1),
num_threads(1),
- constant_sparsity(false),
num_eliminate_blocks(0),
residual_reset_period(10),
row_block_size(Dynamic),
@@ -93,10 +93,6 @@
// If possible, how many threads can the solver use.
int num_threads;
- // If possible cache and reuse the symbolic factorization across
- // multiple calls.
- bool constant_sparsity;
-
// Eliminate 0 to num_eliminate_blocks - 1 from the Normal
// equations to form a schur complement. Only used by the Schur
// complement based solver. The most common use for this parameter
@@ -121,8 +117,8 @@
// It is expected that these parameters are set programmatically
// rather than manually.
//
- // Please see explicit_schur_complement_solver_impl.h for more
- // details.
+ // Please see schur_complement_solver.h and schur_eliminator.h for
+ // more details.
int row_block_size;
int e_block_size;
int f_block_size;
@@ -244,6 +240,7 @@
const PerSolveOptions& per_solve_options,
double* x) = 0;
+ // Factory
static LinearSolver* Create(const Options& options);
};
