void MinToTotal::consume() {
const vector<Real>& envelope = *((const vector<Real>*)_envelope.getTokens());
int minIdx = argmin(envelope);
if (envelope[minIdx] < _min) {
_min = envelope[minIdx];
_minIdx = minIdx + _size;
}
_size += envelope.size();
}
void MinToTotal::compute() {
const vector<Real>& envelope = _envelope.get();
Real& minToTotal = _minToTotal.get();
if (envelope.empty()) {
throw EssentiaException("MinToTotal: envelope is empty, minToTotal is not defined for an empty envelope");
}
minToTotal = Real(argmin(envelope)) / envelope.size();
}
double LineSearch::argmax(Function& f, double minx, double maxx)
{
NegateFunction nf(f);
return argmin(nf, minx, maxx);
}
int main() {
int a[5] = {2, -3, 5, -7, 11};
std::cout << argmin(a, 5) << std::endl;
}
void TempoTapDegara::decodeBeats(map<Real,
vector<vector<Real> > >& transitionMatrix,
const vector<Real>& beatPeriods,
const vector<Real>& beatEndPositions,
const vector<vector<Real> >& biy,
vector<int>& sequenceStates) {
// Transition probability matrix at the begining of the track
size_t currentIndex = 0;
// Best transition information for backtracking
vector<vector<int> > stateBacktracking(_numberStates, vector<int>(_numberFrames));
// HMM cost for each state for the current time
vector<Real> cost(_numberStates, numeric_limits<Real>::max());
cost[0] = 0;
vector<Real> costOld = cost;
vector<Real> diff(_numberStates);
// Dynamic programming
for (size_t t=0; t<_numberFrames; ++t) {
// Evaluate transitions from any state to state event (state 0)
// Look for the minimum cost
for (int i=0; i<_numberStates; ++i) {
diff[i] = costOld[i] - transitionMatrix[beatPeriods[currentIndex]][i][0];
}
int bestState = argmin(diff);
Real bestPath = diff[bestState];
if (bestPath==numeric_limits<Real>::max()) {
bestState = -1;
}
// Save best transtions information for backtracking
stateBacktracking[0][t] = bestState;
// Update cost; the only possible transition is from state to state+1
cost[0] = - biy[0][t] + bestPath;
for (int state=1; state<_numberStates; ++state) {
cost[state] = costOld[state-1]
- transitionMatrix[beatPeriods[currentIndex]][state-1][state]
- biy[state][t];
stateBacktracking[state][t] = state-1;
}
// Update cost at t-1
costOld = cost;
// Find the transition matrix corresponding to next frame
if (t+1 < _numberFrames) {
Real currentTime = (t+1) * _resolutionODF;
for (size_t i=currentIndex+1; i < beatEndPositions.size() &&
beatEndPositions[i] <= currentTime; ++i) {
currentIndex = i;
}
}
}
// Decide which of the final states is the most probable
int finalState = argmin(cost);
// Backtrace through the model
sequenceStates.resize(_numberFrames);
sequenceStates.back() = finalState;
if (_numberFrames >= 2) {
for (size_t t=_numberFrames-2; ; --t) {
sequenceStates[t] = stateBacktracking[sequenceStates[t+1]][t+1];
if (t==0) {
break;
}
}
}
}