#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;
}