Peakfinder

代码说明：

  Basic function to locate and measure the positive peaks in a noisy data sets. Detects peaks by looking for downward zero-crossings in the smoothed third derivative that exceed SlopeThreshold and peak amplitudes that exceed AmpThreshold. Determines, position, height, and approximate width of each peak by least-squares curve-fitting the log of top part of the peak with a parabola.