71 lines
2.5 KiB
C++
71 lines
2.5 KiB
C++
// 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) {
|
|
return rand() % n;
|
|
}
|
|
|
|
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_
|