HillClimbing.cpp
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34 
35 /* Author: Ioan Sucan */
36 
37 #include "ompl/geometric/HillClimbing.h"
38 
39 namespace ompl
40 {
41  namespace magic
42  {
47  static const unsigned int MAX_CLIMB_NO_UPDATE_STEPS = 10;
48  }
49 }
50 
51 bool ompl::geometric::HillClimbing::tryToImprove(const base::GoalRegion &goal, base::State *state, double nearDistance,
52  double *betterGoalDistance) const
53 {
54  double tempDistance;
55  double initialDistance;
56 
57  bool wasValid = valid(state);
58  bool wasValidStart = wasValid;
59 
60  bool wasSatisfied = goal.isSatisfied(state, &initialDistance);
61  bool wasSatisfiedStart = wasSatisfied;
62 
63  double bestDist = initialDistance;
64 
65  base::StateSamplerPtr ss = si_->allocStateSampler();
66  base::State *test = si_->allocState();
67  unsigned int noUpdateSteps = 0;
68 
69  for (unsigned int i = 0; noUpdateSteps < magic::MAX_CLIMB_NO_UPDATE_STEPS && i < maxImproveSteps_; ++i)
70  {
71  bool update = false;
72  ss->sampleUniformNear(test, state, nearDistance);
73  bool isValid = valid(test);
74  bool isSatisfied = goal.isSatisfied(test, &tempDistance);
75  if (!wasValid && isValid)
76  {
77  si_->copyState(state, test);
78  wasValid = true;
79  wasSatisfied = isSatisfied;
80  update = true;
81  }
82  else if (wasValid == isValid)
83  {
84  if (!wasSatisfied && isSatisfied)
85  {
86  si_->copyState(state, test);
87  wasSatisfied = true;
88  update = true;
89  }
90  else if (wasSatisfied == isSatisfied)
91  {
92  if (tempDistance < bestDist)
93  {
94  si_->copyState(state, test);
95  bestDist = tempDistance;
96  update = true;
97  }
98  }
99  }
100  if (update)
101  noUpdateSteps = 0;
102  else
103  noUpdateSteps++;
104  }
105  si_->freeState(test);
106 
107  if (betterGoalDistance)
108  *betterGoalDistance = bestDist;
109  return (bestDist < initialDistance) || (!wasSatisfiedStart && wasSatisfied) || (!wasValidStart && wasValid);
110 }
bool isSatisfied(const State *st) const override
Equivalent to calling isSatisfied(const State *, double *) with a nullptr second argument.
Definition: GoalRegion.cpp:47
A shared pointer wrapper for ompl::base::StateSampler.
static const unsigned int MAX_CLIMB_NO_UPDATE_STEPS
Maximum number of consecutive failures to allow before giving up on improving a state. A failure consists of being unable to sample a state that is closer to the specified goal region.
Main namespace. Contains everything in this library.
Definition: AppBase.h:21
bool tryToImprove(const base::GoalRegion &goal, base::State *state, double nearDistance, double *betterGoalDistance=nullptr) const
Try to improve a state (reduce distance to goal). The updates are performed by sampling near the stat...
Definition of an abstract state.
Definition: State.h:49
Definition of a goal region.
Definition: GoalRegion.h:47