dust3d/third_party/libigl/include/igl/line_search.cpp

51 lines
1.1 KiB
C++

// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2016 Michael Rabinovich
//
// This Source Code Form is subject to the terms of the Mozilla Public License
// v. 2.0. If a copy of the MPL was not distributed with this file, You can
// obtain one at http://mozilla.org/MPL/2.0/.
#include "line_search.h"
IGL_INLINE double igl::line_search(
Eigen::MatrixXd& x,
const Eigen::MatrixXd& d,
double step_size,
std::function<double(Eigen::MatrixXd&)> energy,
double cur_energy)
{
double old_energy;
if (cur_energy > 0)
{
old_energy = cur_energy;
}
else
{
old_energy = energy(x); // no energy was given -> need to compute the current energy
}
double new_energy = old_energy;
int cur_iter = 0; int MAX_STEP_SIZE_ITER = 12;
while (new_energy >= old_energy && cur_iter < MAX_STEP_SIZE_ITER)
{
Eigen::MatrixXd new_x = x + step_size * d;
double cur_e = energy(new_x);
if ( cur_e >= old_energy)
{
step_size /= 2;
}
else
{
x = new_x;
new_energy = cur_e;
}
cur_iter++;
}
return new_energy;
}
#ifdef IGL_STATIC_LIBRARY
#endif