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Match m/z values using interval overlaps

match_mz_foverlaps.Rd

Match two numeric m/z vectors within a ppm tolerance using data.table::foverlaps() on ppm-expanded intervals.

The function returns index pairs (ion1, ion2) and the ppm error (mz.ppm). When length(mz1) > length(mz2), it builds intervals around mz2 using a global window derived from max(ppm.base), then filters to the final ppm.

Usage

match_mz_foverlaps(mz1, mz2, ppm.base = mz1, ppm = 10)

Arguments

mz1

Numeric vector of m/z values (query set 1).

mz2

Numeric vector of m/z values (query set 2).

ppm.base

Numeric vector used as ppm denominator. Defaults to mz1. For typical use, ppm.base should have the same length as the set referenced by ion1 in the returned table (usually mz1).

ppm

Numeric scalar ppm tolerance (default 10).

Value

A data.table with columns:

  • ion1: index in mz1

  • ion2: index in mz2

  • mz.ppm: ppm error (signed when length(mz1) > length(mz2), otherwise absolute)

Examples

mz1 <- c(100.0000, 200.0000)
mz2 <- c(100.0008, 199.9990)
match_mz_foverlaps(mz1, mz2, ppm = 10)
#>     ion1  ion2 mz.ppm
#>    <int> <int>  <num>
#> 1:     1     1      8
#> 2:     2     2      5