| // Ceres Solver - A fast non-linear least squares minimizer |
| // Copyright 2015 Google Inc. All rights reserved. |
| // http://ceres-solver.org/ |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are met: |
| // |
| // * Redistributions of source code must retain the above copyright notice, |
| // this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above copyright notice, |
| // this list of conditions and the following disclaimer in the documentation |
| // and/or other materials provided with the distribution. |
| // * Neither the name of Google Inc. nor the names of its contributors may be |
| // used to endorse or promote products derived from this software without |
| // specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| // 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> |
| |
| #include "ceres/internal/port.h" |
| |
| namespace ceres { |
| |
| inline void SetRandomState(int state) { srand(state); } |
| |
| inline int Uniform(int n) { |
| if (n) { |
| return rand() % n; |
| } else { |
| return 0; |
| } |
| } |
| |
| inline double RandDouble() { |
| double r = static_cast<double>(rand()); |
| 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 |
| |
| #endif // CERES_INTERNAL_RANDOM_H_ |