has_column has_metric_category charge state table ID free metric single run based metric ion source metric MS2 metric MS2 known precursor charges fractions MS:4000063 MS2-PrecZ-3 MS2-PrecZ-4 MS2-PrecZ-1 MS2-PrecZ-2 MS2-PrecZ-5 The fraction of MS/MS precursors of the corresponding charge. The fractions [0,1] are given in the 'Fraction' column, corresponding charges in the 'Charge state' column. The highest charge state is to be interpreted as that charge state or higher. IS-3B IS-3A MS2-PrecZ-more IS-3C the MS2-PrecZ metrics can be directly read from the table respective table rows, the ratios of IS-3 metrics must be derived from the respective table rows, IS-3A as ratio of +1 over +2, IS-3B as ratio of +3 over +2, IS-3C as +4 over +2. MS fraction