peakPeaks {mQTL.NMR} | R Documentation |
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)).
peakPeaks(SpSmooth, dpDerivs, Sp)
SpSmooth |
a vector specifying smoothed spectrum |
dpDerivs |
a vector specifying smoothed derivative of the spectrum |
Sp |
a vector specifying the spectrum of intrest |
identified peaks
Lyamine Hedjazi
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.
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)