source: fact/tools/rootmacros/factfir.C@ 13182

#include <vector>
#include <deque>

// source vector is
void factfir(double b, vector<double> &a, int k, vector<float> &source, vector<float> &dest){
        //dest.clear();

        for (int slice =0; slice < (int)source.size(); slice++) {
                float currentval = 0;

                for (int i=0; i < k ; i++){
                        currentval += a[i] * source[ (slice - i + source.size()) % source.size() ];
                }
                dest[slice] = currentval / b;
        }
}

void sliding_avg(vector<float> &source, vector<float> &dest, unsigned int HalfWidth){
        // make local copy of source, in case source and dest are the same

        deque<float> local;
        local.insert(local.end(), source.begin(), source.end());
        // edge treatment.
        local.insert(local.begin(), HalfWidth, source[0]);
        local.insert(local.end(), HalfWidth, source[source.size()-1]);

        deque<float>::iterator it;

        dest.clear();

        float x;
        for (it=local.begin()+HalfWidth; it<local.end()-HalfWidth; ++it) {

                x=*it;
                float FullWidth = 2*HalfWidth+1;

                for ( unsigned int i=0; i < HalfWidth ; i++){
                        x += *(it+i); // add the right neighbors
                        x += *(it-i); // and don't forget the left neighbors on the left
                }

                dest.push_back(x/FullWidth);
        }
}