Figure 3

Scan averaging algorithm. (a) Related individual scans (here as an example we only show four scans) imported as a complete *.mzXML file are recognized. (b) Peaks are combined into a single peak list and sorted. (c) The full mass range is divided into bins of [m; m+$\frac{m}{R(m)}$] size, starting from the lowest reported mass. The bold dots stand for the lowest mass of each bin, while the arrow length reflects the bin size $\frac{m}{R(m)}$. Within each bin, masses are weight averaged by peak intensities and stored. The procedure (steps (c) and (d)) is repeated two more times on the binned spectrum (not shown). (d) In this way, a single representative average spectrum (d) is produced from several individual scans (a).