Normalize Relative Peak Intensity by Total Ion Current

Called internally by normSpectra. Evaluates the sum of all intensities (TIC) of each spectrum in a dataset. If the TIC of all spectra are not equal, their intensities are multiplied by a normalization factor. Once the TIC of each spectrum has been standardized, the intensity of each peak in all spectra are divided by the normalized TIC. The resulting spectra will have individual TICs of 1. Capable of normalizing 1-6 spectra at once.

norm_rel_TIC(dat, mass_dat, spectra_cols)

Arguments

dat	The name of the spectral data frame, containing m/z data in the first column and spectral intensity data in subsequent columns.
mass_dat	A character string; the name of the column in dat containing the m/z data for the spectrum.
spectra_cols	A character string; the names of the column in dat containing the intensity data for the spectrs to be analyzed.

Value

Returns a new data frame including the original m/z data and normalized intensity data.

References

https://github.com/wesleyburr/subMaldi

Author

Kristen Yeh <kristenyeh@trentu.ca> Wesley Burr <wesleyburr@trentu.ca>

Note

normSpectra

Examples

## Load sample dataset "Master2.rda"
data("Master2")

# Normalize the TIC of "Before1" and "Before2"
ex <- normSpectra(dat = Master2, mass_dat = "full_mz", 
            method = "rel_TIC", spectra_cols = c("Before1", "Before2"))