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Regarding the steps of operating FillChromPeaksParam
The following are the steps I took to analyze GC-MS.
When it comes to FillChromPeaksParam, this function requires the use of XCMSnExp
objects.
The objects I use in the fifth step will be XcmsExperiment
objects.
I don’t know if there is any way to handle the conversion of objects, or Are there any suggestions for optimization steps?
# 1.Mass detection
raw_path <- "/Users/v_v1150n/Desktop/EBC/DISEASE_cdf/20140327_B-169_S041_1.cdf"
raw_data <- readMsExperiment(spectraFiles = raw_path)
cwp <- CentWaveParam(peakwidth = c(5, 20),
noise = 500,
prefilter = c(3, 100),
snthresh = 10,
mzCenterFun = "wMean",
integrate = 1,
fitgauss = FALSE,
)
xdata <- findChromPeaks(raw_data, param = cwp)
# 2.ADAP Chromatogram Builder (GC-MS)
adap_param <- CentWaveParam(
peakwidth = c(5, 20),
noise = 1000,
prefilter = c(3, 1000),
snthresh = 10,
mzCenterFun = "wMean",
integrate = 1,
fitgauss = FALSE,
mzdiff = 0.001,
ppm = 30
)
xdata <- findChromPeaks(raw_data, param = adap_param)
# 3.ADAP Feature Resolver
cwt_param <- CentWaveParam(
peakwidth = c(5, 40),
noise = 500,
snthresh = 4,
mzdiff = 0.001,
integrate = 1,
fitgauss = FALSE,
mzCenterFun = "wMean",
prefilter = c(3, 1000),
ppm = 30
)
xdata <- findChromPeaks(raw_data, param = cwt_param)
# 4.Multivariate Curve Resolution
mcr_param <- PeakDensityParam(
sampleGroups = c(1),
minFraction = 0.5,
bw = 0.2,
minSamples = 1,
binSize = 0.05
)
xdata <- groupChromPeaks(xdata, param = mcr_param)
# 5.ADAP Alignment
align_param <- ObiwarpParam(
binSize = 0.3,
response = 1,
distFun = "cor_opt",
gapInit = 0.3,
gapExtend = 2.4,
factorDiag = 2,
factorGap = 1,
localAlignment = FALSE
)
xdata <- adjustRtime(xdata, param = align_param)
# 6.Gap filling
fill_param <- FillChromPeaksParam(ppm = 5)
xdata <- fillChromPeaks(xdata, param = fill_param)