Randomly perturb the bundle adjustment problem.
1. Add the ability to perturb the camera pose and the
point positions using user specified parameters.
2. Re-order the flags.
3. Minor name correction.
4. Added Box-Mueller generator to random.h
Change-Id: I2c9ce74c237f5bde9a7299cc71b205d1ca9bc742
diff --git a/internal/ceres/random.h b/internal/ceres/random.h
index 769e0b4..cd7a0ea 100644
--- a/internal/ceres/random.h
+++ b/internal/ceres/random.h
@@ -27,19 +27,41 @@
// POSSIBILITY OF SUCH DAMAGE.
//
// Author: keir@google.com (Keir Mierle)
+// sameeragarwal@google.com (Sameer Agarwal)
#ifndef CERES_INTERNAL_RANDOM_H_
#define CERES_INTERNAL_RANDOM_H_
+#include <cmath>
+#include <cstdlib>
+
namespace ceres {
-inline double RandDouble() {
- double r = rand();
- return r / RAND_MAX;
+inline void SetRandomState(int state) {
+ srandom(state);
}
inline int Uniform(int n) {
- return rand() % n;
+ return random() % n;
+}
+
+inline double RandDouble() {
+ double r = static_cast<double>(random());
+ return r / RAND_MAX;
+}
+
+// Box-Muller algorithm for normal random number generation.
+// http://en.wikipedia.org/wiki/Box-Muller_transform
+inline double RandNormal() {
+ double x1, x2, w;
+ do {
+ x1 = 2.0 * RandDouble() - 1.0;
+ x2 = 2.0 * RandDouble() - 1.0;
+ w = x1 * x1 + x2 * x2;
+ } while ( w >= 1.0 || w == 0.0 );
+
+ w = sqrt((-2.0 * log(w)) / w);
+ return x1 * w;
}
} // namespace ceres
