Provides an estimate of m/z peak shifts (dmz) in the real mass spectrum in respect to the corresponding m/z values in the simulated (theoretical) spectrum obtained after Type I and Type II corrections.
dmzFind(sspec, dat, span, ppm)
| sspec | A data frame containing the coordinates of points in the simulated mass spectrum. |
|---|---|
| dat | A typical Lipic or Lipic_It input data frame. |
| span | The "span" parameter value required by the "pick.peaks" function. This function is included in the "LIPIC" package, but belongs to the "ChemometricsWithR" package. |
| ppm | Accuracy threshold (in ppm) within the m/z of a peak in the simulated mass spectrum matches a measured m/z value among those listed in the third column of the input "dat" data frame. |
A modified version of the input "dat" data frame in which the initial dmz values are replaced by those calculated as the difference between the measured and the theoretical m/z values which matched under the "ppm" threshold.
Ron Wehrens: Chemometrics with R. Springer Verlag, Berlin Hei-delberg (2020). DOI: https://doi.org/10.1007/978-3-642-17841-2.