void DrsCalibrateTime::AddT ( const float *  val, const int16_t *  start, signed char  edge = 0  )

inline

Definition at line 977 of file DrsCalib.h.

References first, i, DrsCalibrate::Step::pos, second, and v0.

    {
        if (fNumSamples!=1024 || fNumChannels!=160)
            return;

        // Rising or falling edge detection has the advantage that
        // we are much less sensitive to baseline shifts

        for (size_t ch=0; ch<160; ch++)
        {
            const size_t tm = ch*9+8;

            const int16_t spos = start[tm];
            if (spos<0)
                continue;

            const size_t pos = ch*1024;

            double  p_prev =  0;
            int32_t i_prev = -1;

            for (size_t i=0; i<1024-1; i++)
            {
                const size_t rel = tm*1024 + i;

                const float &v0 = val[rel];  //-avg;
                const float &v1 = val[rel+1];//-avg;

                // If edge is positive ignore all falling edges
                if (edge>0 && v0>0)
                    continue;

                // If edge is negative ignore all falling edges
                if (edge<0 && v0<0)
                    continue;

                // Check if there is a zero crossing
                if ((v0<0 && v1<0) || (v0>0 && v1>0))
                    continue;

                // Calculate the position p of the zero-crossing
                // within the interval [rel, rel+1] relative to rel
                // by linear interpolation.
                const double p = v0==v1 ? 0.5 : v0/(v0-v1);

                // If this was at least the second zero-crossing detected
                if (i_prev>=0)
                {
                    // Calculate the distance l between the
                    // current and the last zero-crossing
                    const double l = i+p - (i_prev+p_prev);

                    // By summation, the average length of each
                    // cell is calculated. For the first and last
                    // fraction of a cell, the fraction is applied
                    // as a weight.
                    const double w0 = 1-p_prev;
                    fStat[pos+(spos+i_prev)%1024].first  += w0*l;
                    fStat[pos+(spos+i_prev)%1024].second += w0;

                    for (size_t k=i_prev+1; k<i; k++)
                    {
                        fStat[pos+(spos+k)%1024].first  += l;
                        fStat[pos+(spos+k)%1024].second += 1;
                    }

                    const double w1 = p;
                    fStat[pos+(spos+i)%1024].first  += w1*l;
                    fStat[pos+(spos+i)%1024].second += w1;
                }

                // Remember this zero-crossing position
                p_prev = p;
                i_prev = i;
            }
        }
        fNumEntries++;
    }