source: fact/tools/rootmacros/zerosearch.C@ 12256

#include <vector>

// searches for zero crossings in a given vector of floats
// for zero crossings in falling edge 
// give edge = -1
// 
// 
// returns pointer to vetctor of ints

vector<int> *zerosearch(vector<float> &input, int edge =-1 , int pre=10, int post=30 ){

        
        vector<int> * zeroPositions = new vector<int>;
        
        for (int sl =pre ; sl < input.size()-post; sl++){
//cout << "sl:" << sl << endl;
                if (input[sl] * input[sl-1] < 0 || input[sl]==0.0 ){ // sign change --> zero crossing OR really zero

                        if ( (input[sl-1] - input[sl]) * edge < 0){ // this is the crossing the user wanted 
                                
                                // check if we go lower than a certain limit in the next few slices
                                for ( int lala=0; lala<post; lala++){
                                        if (input[sl+lala] < -1.5) {
                                                zeroPositions->push_back(sl);
                                                sl += lala;
                                                break;
                                        }
                                }

                        } else if ( (input[sl-1] - input[sl]) * edge > 0){ // this is the zero x-ing the user did not want

                                // do nothing

                        } else { // sl and sl-1 are equal .. don't know waht do to...
        
                        }               

                } 

        } // end of loop over slices - between pre and post

        
        return zeroPositions;
}