peakPeaks {mQTL}R Documentation

Peak picking algorithm

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

peakPeaks(SpSmooth, dpDerivs, Sp)

Arguments

SpSmooth

smoothed spectrum

dpDerivs

smoothed derivative of the spectrum

Sp

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


## Data
Sp=matrix(rnorm(10*13454,mean=0,sd=1), nrow=10,ncol=13454)

## 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)

[Package mQTL version 1.0 Index]