commit 1b7f3b52fb5ff5305bd450b3037fb1fceb2e725a
author Sameer Agarwal <sameeragarwal@google.com> Thu Aug 09 21:46:19 2012 -0700
committer Sameer Agarwal <sameeragarwal@google.com> Fri Aug 10 15:55:31 2012 -0700
tree 83352d999da73df3e6f49fd7e752778ba7468f3e
parent faa117a7e9d4b600360d85bf869050763d679548

Add ability to log solver execution to file.

Change-Id: I9996ba2fed5229fe5d621fbb1a027d4c360cd59d

examples/bundle_adjuster.cc

diff --git a/examples/bundle_adjuster.cc b/examples/bundle_adjuster.cc
index 8f1b38b..1ef0766 100644
--- a/examples/bundle_adjuster.cc
+++ b/examples/bundle_adjuster.cc
@@ -54,6 +54,7 @@
 #include <algorithm>
 #include <cmath>
 #include <cstdio>
+#include <cstdlib>
 #include <string>
 #include <vector>
 
@@ -103,6 +104,7 @@
 DEFINE_int32(random_seed, 38401, "Random seed used to set the state "
              "of the pseudo random number generator used to generate "
              "the pertubations.");
+DEFINE_string(solver_log, "", "File to record the solver execution to.");
 
 namespace ceres {
 namespace examples {
@@ -256,8 +258,28 @@
   SetOrdering(bal_problem, options);
 }
 
+// Uniform random numbers between 0 and 1.
+double UniformRandom() {
+  return static_cast<double>(random()) / static_cast<double>(RAND_MAX);
+}
+
+// Normal random numbers using the Box-Mueller algorithm. Its a bit
+// wasteful, as it generates two but only returns one.
+double RandNormal() {
+  double x1, x2, w, y1, y2;
+  do {
+    x1 = 2.0 * UniformRandom() - 1.0;
+    x2 = 2.0 * UniformRandom() - 1.0;
+    w = x1 * x1 + x2 * x2;
+  } while ( w >= 1.0 );
+
+  w = sqrt((-2.0 * log(w)) / w);
+  y1 = x1 * w;
+  y2 = x2 * w;
+  return y1;
+}
+
 void BuildProblem(BALProblem* bal_problem, Problem* problem) {
-  SetRandomState(FLAGS_random_seed);
   const int point_block_size = bal_problem->point_block_size();
   const int camera_block_size = bal_problem->camera_block_size();
   double* points = bal_problem->mutable_points();
@@ -332,6 +354,7 @@
   BuildProblem(&bal_problem, &problem);
   Solver::Options options;
   SetSolverOptionsFromFlags(&bal_problem, &options);
+  options.solver_log = FLAGS_solver_log;
   Solver::Summary summary;
   Solve(options, &problem, &summary);
   std::cout << summary.FullReport() << "\n";