Comet parameter: precursor_charge

• This parameter specifies the precursor charge range to search.
• This parameter expects to integer values as input.
• If the first input value is 0 then this parameter is ignored and all charge states are searched
• Only in the case where a spectrum does not have a precursor charge will all charges in the specified charge range be searched.
• If the first input value is not 0 then all charge states between (and inclusive of) the first and second input values are searched. Again, only for those spectra with no specified precursor charge state.
• If a precursor charge is present for a particular spectrum, this parameter will not override that charge state and that spectrum will always be searched.
• With the default “0 0” values and a spectrum with no precursor charge, Comet will either search the spectrum as a 1+ or a 2+/3+.
• The default value is “0 0” if this parameter is missing.

Example:

precursor_charge = 0 0
precursor_charge = 0 2 (will search all charge ranges because the first entry is 0)
precursor_charge = 2 6
precursor_charge = 3 3