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Indoor/smc/smoothing/FastKDESmoothing.h
2018-07-12 11:11:11 +02:00

281 lines
11 KiB
C++

#ifndef FASTKDESMOOTHING_H
#define FASTKDESMOOTHING_H
#include <vector>
#include <memory>
#include <algorithm>
#include "BackwardFilterTransition.h"
#include "BackwardFilter.h"
#include "../Particle.h"
#include "../../floorplan/v2/FloorplanHelper.h";
#include "../../grid/Grid.h";
#include "../filtering/resampling/ParticleFilterResampling.h"
#include "../filtering/estimation/ParticleFilterEstimation.h"
#include "../filtering/ParticleFilterEvaluation.h"
#include "../filtering/ParticleFilterInitializer.h"
#include "../filtering/ParticleFilterTransition.h"
#include "../sampling/ParticleTrajectorieSampler.h"
#include "../../math/boxkde/benchmark.h"
#include "../../math/boxkde/DataStructures.h"
#include "../../math/boxkde/Image2D.h"
#include "../../math/boxkde/BoxGaus.h"
#include "../../math/boxkde/Grid2D.h"
#include "../../Assertions.h"
namespace SMC {
template <typename State, typename Control, typename Observation>
class FastKDESmoothing : public BackwardFilter<State, Control, Observation>{
private:
/** all smoothed particles T -> 1*/
std::vector<std::vector<Particle<State>>> backwardParticles;
/** all estimations calculated */
std::vector<State> estimatedStates;
/** the estimation function to use */
std::unique_ptr<ParticleFilterEstimation<State>> estimation;
/** the transition function to use */
std::unique_ptr<ParticleFilterTransition<State, Control>> transition;
/** the resampler to use */
std::unique_ptr<ParticleFilterResampling<State>> resampler;
/** the sampler for drawing trajectories */
std::unique_ptr<ParticleTrajectorieSampler<State>> sampler;
/** the percentage-of-efficient-particles-threshold for resampling */
double nEffThresholdPercent = 0.25;
/** number of realizations to be calculated */
int numParticles;
/** is update called the first time? */
bool firstFunctionCall;
/** boundingBox for the boxKDE */
BoundingBox<float> bb;
/** histogram/grid holding the particles*/
Grid2D<float> grid;
/** bandwith for KDE */
Point2 bandwith;
public:
/** ctor */
FastKDESmoothing(int numParticles, const Floorplan::IndoorMap* map, const int gridsize_cm, const Point2 bandwith) {
this->numParticles = numParticles;
//backwardParticles.reserve(numParticles);
this->firstFunctionCall = true;
const Point3 maxBB = FloorplanHelper::getBBox(map).getMax() * 100.0;
const Point3 minBB = FloorplanHelper::getBBox(map).getMin() * 100.0;
this->bb = BoundingBox<float>(minBB.x, maxBB.x, minBB.y, maxBB.y);
// Create histogram
size_t nBinsX = static_cast<size_t>((maxBB.x - minBB.x) / gridsize_cm);
size_t nBinsY = static_cast<size_t>((maxBB.y - minBB.y) / gridsize_cm);
this->grid = Grid2D<float>(bb, nBinsX, nBinsY);
this->bandwith = bandwith;
}
/** dtor */
~FastKDESmoothing() {
backwardParticles.clear();
estimatedStates.clear();
}
/** access to all backward / smoothed particles */
const std::vector<std::vector<Particle<State>>>& getbackwardParticles() {
return backwardParticles;
}
/** set the estimation method to use */
void setEstimation(std::unique_ptr<ParticleFilterEstimation<State>> estimation) {
Assert::isNotNull(estimation, "setEstimation() MUST not be called with a nullptr!");
this->estimation = std::move(estimation);
}
/** set the transition method to use */
void setTransition(std::unique_ptr<ParticleFilterTransition<State, Control>> transition) {
Assert::isNotNull(transition, "setTransition() MUST not be called with a nullptr!");
this->transition = std::move(transition);
}
/** set the transition method to use */
void setTransition(std::unique_ptr<BackwardFilterTransition<State, Control>> transition) {
Assert::doThrow("Do not use a backward transition for fast smoothing! Forward Transition");
//TODO: two times setTransition is not the best solution
}
/** set the resampling method to use */
void setResampling(std::unique_ptr<ParticleFilterResampling<State>> resampler) {
Assert::isNotNull(resampler, "setResampling() MUST not be called with a nullptr!");
this->resampler = std::move(resampler);
}
/** set the sampler method to use */
void setSampler(std::unique_ptr<ParticleTrajectorieSampler<State>> sampler){
Assert::isNotNull(sampler, "setSampler() MUST not be called with a nullptr!");
this->sampler = std::move(sampler);
}
/** set the resampling threshold as the percentage of efficient particles */
void setNEffThreshold(const double thresholdPercent) {
this->nEffThresholdPercent = thresholdPercent;
}
/** get the used transition method */
BackwardFilterTransition<State, Control>* getTransition() {
return nullptr;
}
/**
* @brief update
* @param forwardHistory
* @return
*/
State update(ForwardFilterHistory<State, Control, Observation>& forwardHistory, int lag = 666) {
// sanity checks (if enabled)
Assert::isNotNull(transition, "transition MUST not be null! call setTransition() first!");
Assert::isNotNull(estimation, "estimation MUST not be null! call setEstimation() first!");
//init for backward filtering
std::vector<Particle<State>> smoothedParticles;
smoothedParticles.reserve(numParticles);
firstFunctionCall = true;
// if no lag is given, we have a fixed interval smoothing
if(lag == 666){
lag = forwardHistory.size() - 1;
}
//check if we have enough data for lag
if(forwardHistory.size() <= lag){
lag = forwardHistory.size() - 1;
}
//iterate through all forward filtering steps
for(int i = 0; i <= lag; ++i){
std::vector<Particle<State>> forwardParticlesForTransition_t1 = forwardHistory.getParticleSet(i);
//storage for single trajectories / smoothed particles
smoothedParticles.clear();
// Choose \tilde x_T = x^(i)_T with probability w^(i)_T
// Therefore sample independently from the categorical distribution of weights.
if(firstFunctionCall){
smoothedParticles = sampler->drawTrajectorie(forwardParticlesForTransition_t1, numParticles);
firstFunctionCall = false;
backwardParticles.push_back(smoothedParticles);
State est = estimation->estimate(smoothedParticles);
estimatedStates.push_back(est);
continue;
}
// transition p(q_t+1* | q_t): so we are performing again a forward transition step.
// we are doing this to track single particles between two timesteps! normaly, resampling would destroy
// any identifier given to particles.
// Node: at this point we can integrate future observation and control information for better smoothing
Control controls = forwardHistory.getControl(i-1);
Observation obs = forwardHistory.getObservation(i-1);
transition->transition(forwardParticlesForTransition_t1, &controls);
// KDE auf q_t+1 Samples = p(q_t+1 | o_1:T) - Smoothed samples from the future
grid.clear();
for (Particle<State> p : backwardParticles.back())
{
grid.add(p.state.position.x_cm, p.state.position.y_cm, p.weight);
}
int nFilt = 3;
float sigmaX = bandwith.x / grid.binSizeX;
float sigmaY = bandwith.y / grid.binSizeY;
BoxGaus<float> boxGaus;
boxGaus.approxGaus(grid.image(), sigmaX, sigmaY, nFilt);
/**
* Das hier wird nicht funktionieren!
* Wir machen eine Transition von t zu t+1 und nehmen dann diese position um von der kde aus t+1 ein
* Gewicht zu erhalten... aber das bringt ja nichts, diese Gewicht haben wir doch schon auf den partikeln in t+1
* die transition macht ja nicht 2x was anderes, sondern wieder genau das gleiche.
* was das smoothing gut macht, sind die Faltungen mit allen Partikeln (jeder mit jedem vergleichen).
**/
// Apply Position from Samples from q_t+1* into KDE of p(q_t+1 | o_1:T) to get p(q_t+1* | o_1:T)
// Calculate new weight w(q_(t|T)) = w(q_t) * p(q_t+1* | o_1:T) * p(q_t+1* | q_t) * normalisation
smoothedParticles = forwardHistory.getParticleSet(i);
for(Particle<State> p : smoothedParticles){
p.weight = p.weight * grid.fetch(p.state.position.x_cm, p.state.position.y_cm);
//Assert::isNot0(p.weight, "smoothed particle has zero weight");
}
//normalization
auto lambda = [](double current, const Particle<State>& a){return current + a.weight; };
double weightSumSmoothed = std::accumulate(smoothedParticles.begin(), smoothedParticles.end(), 0.0, lambda);
if(weightSumSmoothed != 0.0){
for (Particle<State> p : smoothedParticles){
p.weight /= weightSumSmoothed;
}
//check if normalization worked
double normWeightSum = std::accumulate(smoothedParticles.begin(), smoothedParticles.end(), 0.0, lambda);
Assert::isNear(normWeightSum, 1.0, 0.001, "Smoothed weights do not sum to 1");
} else {
Assert::doThrow("Weight Sum of smoothed particles is zero!");
}
if(resampler)
{
//TODO - does this even make sense?
Assert::doThrow("Warning - Resampling is not yet implemented!");
}
// push_back the smoothedParticles
backwardParticles.push_back(smoothedParticles);
// estimate the current state
if(lag == (forwardHistory.size() - 1) ){ //fixed interval
State est = estimation->estimate(smoothedParticles);
estimatedStates.push_back(est);
}
else if (i == lag) { //fixed lag
State est = estimation->estimate(smoothedParticles);
estimatedStates.push_back(est);
}
}
return estimatedStates.back();
}
std::vector<State> getEstimations(){
return estimatedStates;
}
};
}
#endif // FASTKDESMOOTHING_H