commit b16e118b96c55451c0d8556f3c5b52ad36b69cac
author Sameer Agarwal <sameeragarwal@google.com> Mon Nov 25 05:47:43 2013 -0800
committer Sameer Agarwal <sameeragarwal@google.com> Tue Nov 26 10:00:03 2013 -0800
tree 2d5322d2f9fafde0a298e95356f70962acc57957
parent 5794d41be2d8d6a67dcdfe607e66050f0ac04c55

Better error checking and reporting for linear solvers.

A lot of error checking cruft has accumulated over the years
in the various linear solvers. This change makes the error reporting
more robust and consistent across the various solvers.

Preconditioners are not covered by this change and will be the
subject of a future change.

Change-Id: Ibeb2572a1e67758953dde8d12e3abc6d1df9052d

internal/ceres/visibility_based_preconditioner.cc

diff --git a/internal/ceres/visibility_based_preconditioner.cc b/internal/ceres/visibility_based_preconditioner.cc
index aeaab12..e0737f2 100644
--- a/internal/ceres/visibility_based_preconditioner.cc
+++ b/internal/ceres/visibility_based_preconditioner.cc
@@ -435,14 +435,19 @@
   // matrix contains the values.
   lhs->stype = 1;
 
+  // TODO(sameeragarwal): Refactor to pipe this up and out.
+  string status;
+
   // Symbolic factorization is computed if we don't already have one handy.
   if (factor_ == NULL) {
-    factor_ = ss_.BlockAnalyzeCholesky(lhs, block_size_, block_size_);
+    factor_ = ss_.BlockAnalyzeCholesky(lhs, block_size_, block_size_, &status);
   }
 
-  LinearSolverTerminationType status = ss_.Cholesky(lhs, factor_);
+  const LinearSolverTerminationType termination_type =
+      (factor_ != NULL) ? ss_.Cholesky(lhs, factor_, &status) : FATAL_ERROR;
+
   ss_.Free(lhs);
-  return status;
+  return termination_type;
 }
 
 void VisibilityBasedPreconditioner::RightMultiply(const double* x,
@@ -453,7 +458,9 @@
 
   const int num_rows = m_->num_rows();
   memcpy(CHECK_NOTNULL(tmp_rhs_)->x, x, m_->num_rows() * sizeof(*x));
-  cholmod_dense* solution = CHECK_NOTNULL(ss->Solve(factor_, tmp_rhs_));
+  // TODO(sameeragarwal): Better error handling.
+  string status;
+  cholmod_dense* solution = CHECK_NOTNULL(ss->Solve(factor_, tmp_rhs_, &status));
   memcpy(y, solution->x, sizeof(*y) * num_rows);
   ss->Free(solution);
 }