opencv/modules/ml/src/rtrees.cpp
2024-03-05 12:15:39 +03:00

532 lines
20 KiB
C++

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#include "precomp.hpp"
namespace cv {
namespace ml {
//////////////////////////////////////////////////////////////////////////////////////////
// Random trees //
//////////////////////////////////////////////////////////////////////////////////////////
RTreeParams::RTreeParams()
{
CV_TRACE_FUNCTION();
calcVarImportance = false;
nactiveVars = 0;
termCrit = TermCriteria(TermCriteria::EPS + TermCriteria::COUNT, 50, 0.1);
}
RTreeParams::RTreeParams(bool _calcVarImportance,
int _nactiveVars,
TermCriteria _termCrit )
{
CV_TRACE_FUNCTION();
calcVarImportance = _calcVarImportance;
nactiveVars = _nactiveVars;
termCrit = _termCrit;
}
class DTreesImplForRTrees CV_FINAL : public DTreesImpl
{
public:
DTreesImplForRTrees()
{
CV_TRACE_FUNCTION();
params.setMaxDepth(5);
params.setMinSampleCount(10);
params.setRegressionAccuracy(0.f);
params.useSurrogates = false;
params.setMaxCategories(10);
params.setCVFolds(0);
params.use1SERule = false;
params.truncatePrunedTree = false;
params.priors = Mat();
oobError = 0;
}
virtual ~DTreesImplForRTrees() {}
void clear() CV_OVERRIDE
{
CV_TRACE_FUNCTION();
DTreesImpl::clear();
oobError = 0.;
}
const vector<int>& getActiveVars() CV_OVERRIDE
{
CV_TRACE_FUNCTION();
RNG &rng = theRNG();
int i, nvars = (int)allVars.size(), m = (int)activeVars.size();
for( i = 0; i < nvars; i++ )
{
int i1 = rng.uniform(0, nvars);
int i2 = rng.uniform(0, nvars);
std::swap(allVars[i1], allVars[i2]);
}
for( i = 0; i < m; i++ )
activeVars[i] = allVars[i];
return activeVars;
}
void startTraining( const Ptr<TrainData>& trainData, int flags ) CV_OVERRIDE
{
CV_TRACE_FUNCTION();
CV_Assert(!trainData.empty());
DTreesImpl::startTraining(trainData, flags);
int nvars = w->data->getNVars();
int i, m = rparams.nactiveVars > 0 ? rparams.nactiveVars : cvRound(std::sqrt((double)nvars));
m = std::min(std::max(m, 1), nvars);
allVars.resize(nvars);
activeVars.resize(m);
for( i = 0; i < nvars; i++ )
allVars[i] = varIdx[i];
}
void endTraining() CV_OVERRIDE
{
CV_TRACE_FUNCTION();
DTreesImpl::endTraining();
vector<int> a, b;
std::swap(allVars, a);
std::swap(activeVars, b);
}
bool train( const Ptr<TrainData>& trainData, int flags ) CV_OVERRIDE
{
CV_TRACE_FUNCTION();
RNG &rng = theRNG();
CV_Assert(!trainData.empty());
startTraining(trainData, flags);
int treeidx, ntrees = (rparams.termCrit.type & TermCriteria::COUNT) != 0 ?
rparams.termCrit.maxCount : 10000;
int i, j, k, vi, vi_, n = (int)w->sidx.size();
int nclasses = (int)classLabels.size();
double eps = (rparams.termCrit.type & TermCriteria::EPS) != 0 &&
rparams.termCrit.epsilon > 0 ? rparams.termCrit.epsilon : 0.;
vector<int> sidx(n);
vector<uchar> oobmask(n);
vector<int> oobidx;
vector<int> oobperm;
vector<double> oobres(n, 0.);
vector<int> oobcount(n, 0);
vector<int> oobvotes(n*nclasses, 0);
int nvars = w->data->getNVars();
int nallvars = w->data->getNAllVars();
const int* vidx = !varIdx.empty() ? &varIdx[0] : 0;
vector<float> samplebuf(nallvars);
Mat samples = w->data->getSamples();
float* psamples = samples.ptr<float>();
size_t sstep0 = samples.step1(), sstep1 = 1;
Mat sample0, sample(nallvars, 1, CV_32F, &samplebuf[0]);
int predictFlags = _isClassifier ? (PREDICT_MAX_VOTE + RAW_OUTPUT) : PREDICT_SUM;
bool calcOOBError = eps > 0 || rparams.calcVarImportance;
double max_response = 0.;
if( w->data->getLayout() == COL_SAMPLE )
std::swap(sstep0, sstep1);
if( !_isClassifier )
{
for( i = 0; i < n; i++ )
{
double val = std::abs(w->ord_responses[w->sidx[i]]);
max_response = std::max(max_response, val);
}
CV_Assert(fabs(max_response) > 0);
}
if( rparams.calcVarImportance )
varImportance.resize(nallvars, 0.f);
for( treeidx = 0; treeidx < ntrees; treeidx++ )
{
for( i = 0; i < n; i++ )
oobmask[i] = (uchar)1;
for( i = 0; i < n; i++ )
{
j = rng.uniform(0, n);
sidx[i] = w->sidx[j];
oobmask[j] = (uchar)0;
}
int root = addTree( sidx );
if( root < 0 )
return false;
if( calcOOBError )
{
oobidx.clear();
for( i = 0; i < n; i++ )
{
if( oobmask[i] )
oobidx.push_back(i);
}
int n_oob = (int)oobidx.size();
// if there is no out-of-bag samples, we can not compute OOB error
// nor update the variable importance vector; so we proceed to the next tree
if( n_oob == 0 )
continue;
double ncorrect_responses = 0.;
oobError = 0.;
for( i = 0; i < n_oob; i++ )
{
j = oobidx[i];
sample = Mat( nallvars, 1, CV_32F, psamples + sstep0*w->sidx[j], sstep1*sizeof(psamples[0]) );
double val = predictTrees(Range(treeidx, treeidx+1), sample, predictFlags);
double sample_weight = w->sample_weights[w->sidx[j]];
if( !_isClassifier )
{
oobres[j] += val;
oobcount[j]++;
double true_val = w->ord_responses[w->sidx[j]];
double a = oobres[j]/oobcount[j] - true_val;
oobError += sample_weight * a*a;
val = (val - true_val)/max_response;
ncorrect_responses += std::exp( -val*val );
}
else
{
int ival = cvRound(val);
//Voting scheme to combine OOB errors of each tree
int* votes = &oobvotes[j*nclasses];
votes[ival]++;
int best_class = 0;
for( k = 1; k < nclasses; k++ )
if( votes[best_class] < votes[k] )
best_class = k;
int diff = best_class != w->cat_responses[w->sidx[j]];
oobError += sample_weight * diff;
ncorrect_responses += diff == 0;
}
}
oobError /= n_oob;
if( rparams.calcVarImportance && n_oob > 1 )
{
Mat sample_clone;
oobperm.resize(n_oob);
for( i = 0; i < n_oob; i++ )
oobperm[i] = oobidx[i];
for (i = n_oob - 1; i > 0; --i) //Randomly shuffle indices so we can permute features
{
int r_i = rng.uniform(0, n_oob);
std::swap(oobperm[i], oobperm[r_i]);
}
for( vi_ = 0; vi_ < nvars; vi_++ )
{
vi = vidx ? vidx[vi_] : vi_; //Ensure that only the user specified predictors are used for training
double ncorrect_responses_permuted = 0;
for( i = 0; i < n_oob; i++ )
{
j = oobidx[i];
int vj = oobperm[i];
sample0 = Mat( nallvars, 1, CV_32F, psamples + sstep0*w->sidx[j], sstep1*sizeof(psamples[0]) );
sample0.copyTo(sample_clone); //create a copy so we don't mess up the original data
sample_clone.at<float>(vi) = psamples[sstep0*w->sidx[vj] + sstep1*vi];
double val = predictTrees(Range(treeidx, treeidx+1), sample_clone, predictFlags);
if( !_isClassifier )
{
val = (val - w->ord_responses[w->sidx[j]])/max_response;
ncorrect_responses_permuted += exp( -val*val );
}
else
{
ncorrect_responses_permuted += cvRound(val) == w->cat_responses[w->sidx[j]];
}
}
varImportance[vi] += (float)(ncorrect_responses - ncorrect_responses_permuted);
}
}
}
if( calcOOBError && oobError < eps )
break;
}
if( rparams.calcVarImportance )
{
for( vi_ = 0; vi_ < nallvars; vi_++ )
varImportance[vi_] = std::max(varImportance[vi_], 0.f);
normalize(varImportance, varImportance, 1., 0, NORM_L1);
}
endTraining();
return true;
}
void writeTrainingParams( FileStorage& fs ) const CV_OVERRIDE
{
CV_TRACE_FUNCTION();
DTreesImpl::writeTrainingParams(fs);
fs << "nactive_vars" << rparams.nactiveVars;
}
void write( FileStorage& fs ) const CV_OVERRIDE
{
CV_TRACE_FUNCTION();
if( roots.empty() )
CV_Error( cv::Error::StsBadArg, "RTrees have not been trained" );
writeFormat(fs);
writeParams(fs);
fs << "oob_error" << oobError;
if( !varImportance.empty() )
fs << "var_importance" << varImportance;
int k, ntrees = (int)roots.size();
fs << "ntrees" << ntrees
<< "trees" << "[";
for( k = 0; k < ntrees; k++ )
{
fs << "{";
writeTree(fs, roots[k]);
fs << "}";
}
fs << "]";
}
void readParams( const FileNode& fn ) CV_OVERRIDE
{
CV_TRACE_FUNCTION();
DTreesImpl::readParams(fn);
FileNode tparams_node = fn["training_params"];
rparams.nactiveVars = (int)tparams_node["nactive_vars"];
}
void read( const FileNode& fn ) CV_OVERRIDE
{
CV_TRACE_FUNCTION();
clear();
//int nclasses = (int)fn["nclasses"];
//int nsamples = (int)fn["nsamples"];
oobError = (double)fn["oob_error"];
int ntrees = (int)fn["ntrees"];
readVectorOrMat(fn["var_importance"], varImportance);
readParams(fn);
FileNode trees_node = fn["trees"];
FileNodeIterator it = trees_node.begin();
CV_Assert( ntrees == (int)trees_node.size() );
for( int treeidx = 0; treeidx < ntrees; treeidx++, ++it )
{
FileNode nfn = (*it)["nodes"];
readTree(nfn);
}
}
void getVotes( InputArray input, OutputArray output, int flags ) const
{
CV_TRACE_FUNCTION();
CV_Assert( !roots.empty() );
int nclasses = (int)classLabels.size(), ntrees = (int)roots.size();
Mat samples = input.getMat(), results;
int i, j, nsamples = samples.rows;
int predictType = flags & PREDICT_MASK;
if( predictType == PREDICT_AUTO )
{
predictType = !_isClassifier || (classLabels.size() == 2 && (flags & RAW_OUTPUT) != 0) ?
PREDICT_SUM : PREDICT_MAX_VOTE;
}
if( predictType == PREDICT_SUM )
{
output.create(nsamples, ntrees, CV_32F);
results = output.getMat();
for( i = 0; i < nsamples; i++ )
{
for( j = 0; j < ntrees; j++ )
{
float val = predictTrees( Range(j, j+1), samples.row(i), flags);
results.at<float> (i, j) = val;
}
}
} else
{
vector<int> votes;
output.create(nsamples+1, nclasses, CV_32S);
results = output.getMat();
for ( j = 0; j < nclasses; j++)
{
results.at<int> (0, j) = classLabels[j];
}
for( i = 0; i < nsamples; i++ )
{
votes.clear();
for( j = 0; j < ntrees; j++ )
{
int val = (int)predictTrees( Range(j, j+1), samples.row(i), flags);
votes.push_back(val);
}
for ( j = 0; j < nclasses; j++)
{
results.at<int> (i+1, j) = (int)std::count(votes.begin(), votes.end(), classLabels[j]);
}
}
}
}
double getOOBError() const {
return oobError;
}
RTreeParams rparams;
double oobError;
vector<float> varImportance;
vector<int> allVars, activeVars;
};
class RTreesImpl CV_FINAL : public RTrees
{
public:
inline bool getCalculateVarImportance() const CV_OVERRIDE { return impl.rparams.calcVarImportance; }
inline void setCalculateVarImportance(bool val) CV_OVERRIDE { impl.rparams.calcVarImportance = val; }
inline int getActiveVarCount() const CV_OVERRIDE { return impl.rparams.nactiveVars; }
inline void setActiveVarCount(int val) CV_OVERRIDE { impl.rparams.nactiveVars = val; }
inline TermCriteria getTermCriteria() const CV_OVERRIDE { return impl.rparams.termCrit; }
inline void setTermCriteria(const TermCriteria& val) CV_OVERRIDE { impl.rparams.termCrit = val; }
inline int getMaxCategories() const CV_OVERRIDE { return impl.params.getMaxCategories(); }
inline void setMaxCategories(int val) CV_OVERRIDE { impl.params.setMaxCategories(val); }
inline int getMaxDepth() const CV_OVERRIDE { return impl.params.getMaxDepth(); }
inline void setMaxDepth(int val) CV_OVERRIDE { impl.params.setMaxDepth(val); }
inline int getMinSampleCount() const CV_OVERRIDE { return impl.params.getMinSampleCount(); }
inline void setMinSampleCount(int val) CV_OVERRIDE { impl.params.setMinSampleCount(val); }
inline int getCVFolds() const CV_OVERRIDE { return impl.params.getCVFolds(); }
inline void setCVFolds(int val) CV_OVERRIDE { impl.params.setCVFolds(val); }
inline bool getUseSurrogates() const CV_OVERRIDE { return impl.params.getUseSurrogates(); }
inline void setUseSurrogates(bool val) CV_OVERRIDE { impl.params.setUseSurrogates(val); }
inline bool getUse1SERule() const CV_OVERRIDE { return impl.params.getUse1SERule(); }
inline void setUse1SERule(bool val) CV_OVERRIDE { impl.params.setUse1SERule(val); }
inline bool getTruncatePrunedTree() const CV_OVERRIDE { return impl.params.getTruncatePrunedTree(); }
inline void setTruncatePrunedTree(bool val) CV_OVERRIDE { impl.params.setTruncatePrunedTree(val); }
inline float getRegressionAccuracy() const CV_OVERRIDE { return impl.params.getRegressionAccuracy(); }
inline void setRegressionAccuracy(float val) CV_OVERRIDE { impl.params.setRegressionAccuracy(val); }
inline cv::Mat getPriors() const CV_OVERRIDE { return impl.params.getPriors(); }
inline void setPriors(const cv::Mat& val) CV_OVERRIDE { impl.params.setPriors(val); }
inline void getVotes(InputArray input, OutputArray output, int flags) const CV_OVERRIDE {return impl.getVotes(input,output,flags);}
RTreesImpl() {}
virtual ~RTreesImpl() CV_OVERRIDE {}
String getDefaultName() const CV_OVERRIDE { return "opencv_ml_rtrees"; }
bool train( const Ptr<TrainData>& trainData, int flags ) CV_OVERRIDE
{
CV_TRACE_FUNCTION();
CV_Assert(!trainData.empty());
if (impl.getCVFolds() != 0)
CV_Error(Error::StsBadArg, "Cross validation for RTrees is not implemented");
return impl.train(trainData, flags);
}
float predict( InputArray samples, OutputArray results, int flags ) const CV_OVERRIDE
{
CV_TRACE_FUNCTION();
CV_CheckEQ(samples.cols(), getVarCount(), "");
return impl.predict(samples, results, flags);
}
void write( FileStorage& fs ) const CV_OVERRIDE
{
CV_TRACE_FUNCTION();
impl.write(fs);
}
void read( const FileNode& fn ) CV_OVERRIDE
{
CV_TRACE_FUNCTION();
impl.read(fn);
}
Mat getVarImportance() const CV_OVERRIDE { return Mat_<float>(impl.varImportance, true); }
int getVarCount() const CV_OVERRIDE { return impl.getVarCount(); }
bool isTrained() const CV_OVERRIDE { return impl.isTrained(); }
bool isClassifier() const CV_OVERRIDE { return impl.isClassifier(); }
const vector<int>& getRoots() const CV_OVERRIDE { return impl.getRoots(); }
const vector<Node>& getNodes() const CV_OVERRIDE { return impl.getNodes(); }
const vector<Split>& getSplits() const CV_OVERRIDE { return impl.getSplits(); }
const vector<int>& getSubsets() const CV_OVERRIDE { return impl.getSubsets(); }
double getOOBError() const CV_OVERRIDE { return impl.getOOBError(); }
DTreesImplForRTrees impl;
};
Ptr<RTrees> RTrees::create()
{
CV_TRACE_FUNCTION();
return makePtr<RTreesImpl>();
}
//Function needed for Python and Java wrappers
Ptr<RTrees> RTrees::load(const String& filepath, const String& nodeName)
{
CV_TRACE_FUNCTION();
return Algorithm::load<RTrees>(filepath, nodeName);
}
}}
// End of file.