normaliseSpectrum: Spectrum normalisation

In Yang0014/MassSpectrometry: Tools for Glyco Native Mass Spectrometry Analysis

Description

Three normalisation methods for spectrum.

Usage

  normaliseSpectrum(x, method = c("sum", "max", "unit"))

Arguments

x	numeric(n): the intensity values at each m/z.
method	character(1): the method for normalisation. "sum": the sum of all the intensity values is taken as unity, and each peak is normalised by dividing by the sum. "max": each peak is normalised by dividing by the highest peak. "unit": each peak is normalised by dividing by the squared root of the sum of the squred peaks, sqrt(sum(I_i^2)), which leads to each spectrum being a vector of unit length.

Details

Rasmussen and Isenhour studied these three normalisation methods and they found that all the normalization methods and search methods gave similar results, although the "sum" method seems the to be best normalization method.

Value

numeric(n) vector of normalised peaks.

Author(s)

Yang Yang

References

Rasmussen, G.T., and Isenhour, T.L. (1979). The Evaluation of Mass Spectral Search Algorithms. J. Chem. Inf. Comput. Sci. 19, 179-186.

Examples

  x <- c(50,100,10,200)
  normaliseSpectrum(x, method="sum")
  normaliseSpectrum(x, method="max")
  normaliseSpectrum(x, method="unit")

Yang0014/MassSpectrometry documentation built on May 10, 2019, 12:05 a.m.