Filtering spectra by m/z

[jorainer]

There are two different use cases of filtering a spectrum by m/z:

• filter by an m/z range (that's what the MSnbase::filterMz is doing): keep only peaks that are within the provided m/z range.
• filter a spectrum keeping only peaks that match the provided m/z value(s). This is something I need at present: given a spectrum, find/filter to the peaks that match a set of m/z values (from different ions of a compound).

We could now either: 1) implement two separate filter methods filterMzRange for the first and filterMz for the latter use case. 2) implement a single filterMz with a parameter range = TRUE to switch between range- or match-based filtering.

@sgibb @lgatto any comments, ideas?

[lgatto]

I prefer two separate functions rather than a parameter and would suggest

• filterMzRange()
• filterMzValues()

[jorainer]

Fine for me. Thanks @lgatto