This function returns an emetaFilt object for use with
applyFilt to filter a 'peakData' or 'compoundData' object based
on a column in e\_meta
emeta_filter(ftmsObj, cname)an object of the class 'peakData' or 'compoundData'
character string giving name of column in e_meta which
filter should be based upon.
Object of class 'emetaFilt' that contains the molecule identifier and the e\_meta column of interest. This can be used in conjunction with
applyFilt to filter peaks outside of a specified range of
values.
data("exampleProcessedPeakData")
# filter peaks based on Oxygen to Carbon ratio #
filter_object1 = emeta_filter(exampleProcessedPeakData, cname = "OtoC_ratio")
# filter to keep peaks with O:C ratio greater than or equal to 0.5 #
filtered_data = applyFilt(filter_object1, exampleProcessedPeakData, min_val = 0.5)
# filter to keep peaks with O:C ratio greater than or equal to 0.5 and less than or equal to 1 #
filtered_data = applyFilt(filter_object1, exampleProcessedPeakData, min_val = 0.5, max_val = 1)
# filter peaks based on molecular formula #
filter_object2 = emeta_filter(exampleProcessedPeakData, cname = "MolForm")
# filter to keep peaks with molecular formula of C12H14O12
filtered_data = applyFilt(filter_object2, exampleProcessedPeakData, cats = "C12H14O12")
# filter to keep peaks with molecular formula of C12H14O12 and keep NA MolForm peaks
filtered_data = applyFilt(filter_object2, exampleProcessedPeakData,
cats = "C12H14O12", na.rm = FALSE)