Subset data based on specified range of mass values
mass_filter(ftmsObj)an object of class 'peakData' or 'compoundData', typically a result of as.peakData or mapPeaksToCompounds.
an object of class 'massFilt'
Use this in conjunction with applyFilt to retain peaks which have a mass between min_mass and max_mass (inclusive) and filter all other peaks from the data.