peakPeaks: Peak picking algorithm

Description Usage Arguments Value Author(s) References See Also Examples

View source: R/peakPeaks.R

Description

Identification of peaks in metabolomic data based on the calculation of smoothed derivates using Savitzky-Golay filter. The peak is identified if derivative crosses zero, i.e. sign(X'(i))>sing(X'(i+1)).

Usage

1
peakPeaks(SpSmooth, dpDerivs, Sp)

Arguments

SpSmooth

a vector specifying smoothed spectrum

dpDerivs

a vector specifying smoothed derivative of the spectrum

Sp

a vector specifying the spectrum of intrest

Value

identified peaks

Author(s)

Lyamine Hedjazi

References

Veselkov,K. et al (2009) Recursive Segment-Wise Peak Alignment of Biological 1H NMR Spectra for Improved Metabolic Biomarker Recovery, Anal. Chem., 81(1), 56-66.

See Also

sgolayDeriv

Examples

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
load_datafiles()
Sp<-t(read.table(phenofile))

## Peak picking
Spectrum<-Sp[1,]
iOrder <- 3
iFrameLen<- 11

SpDerivs<-sgolayDeriv(Spectrum,iOrder,iFrameLen,2)
SpSmooth<-sgolayDeriv(Spectrum,iOrder,iFrameLen,1)
peaks<-peakPeaks(SpSmooth,SpDerivs,Spectrum)

mQTL.NMR documentation built on Nov. 1, 2018, 2:13 a.m.