SetPeakParam: Set parameters for peak profiling and parameters optimization

View source: R/Params_db.R

SetPeakParamR Documentation

Set parameters for peak profiling and parameters optimization

Description

This function sets all the parameters used for downstream pre-processing of user's raw MS data based on specific Liquid chromatography–mass spectrometry (LC-MS) platform or parameters optimization. The database will be under an real-time update based on the progress in this field.

Usage

SetPeakParam(
  platform = "general",
  Peak_method = "centWave",
  RT_method = "loess",
  mzdiff,
  snthresh,
  bw,
  ppm,
  min_peakwidth,
  max_peakwidth,
  noise,
  prefilter,
  value_of_prefilter,
  fwhm,
  steps,
  sigma,
  peakBinSize,
  max,
  criticalValue,
  consecMissedLimit,
  unions,
  checkBack,
  withWave,
  profStep,
  minFraction,
  minSamples,
  maxFeatures,
  mzCenterFun,
  integrate,
  extra,
  span,
  smooth,
  family,
  fitgauss,
  polarity,
  perc_fwhm,
  mz_abs_iso,
  max_charge,
  max_iso,
  corr_eic_th,
  mz_abs_add,
  adducts,
  rmConts,
  BlankSub
)

Arguments

platform

Character, specify the LC-MS platform used in pratice, including "UPLC-Q/E", "UPLC-Q/TOF","UPLC-T/TOF","UPLC-Ion_Trap","UPLC-Orbitrap","UPLC-G2S","HPLC-Q/TOF","HPLC-Ion_Trap","HPLC-Orbitrap","HPLC-S/Q". Default is "general", which is a more common option for all platform. If the platform is not listed above, please use this one.

Peak_method

Character, specify the algorithm to perform peak detection. "centwave" to use the CentWave algorithm, and "matchedFilter" to use the MatchedFilter algorithm.

RT_method

Character, specify the algorithm to perform tetention time alignment, including "loess" and "obiwarp". Default is "loess".

mzdiff

Numeric, specify the minimum m/z difference for signals to be considered as different features when retention times are overlapping.

snthresh

Numeric, specify the signal to noise threshold. Work for both 'centwave' and 'matchedFilter'.

bw

Numeric, specify the band width (sd or half width at half maximum) of gaussian smoothing kernel to be applied during peak grouping.

ppm

Numeric, specify the mass error in ppm.

min_peakwidth

Numeric, specify the minimum peak width in seconds.Only work for 'centWave'.

max_peakwidth

Numeric, specify the maximum peak width in seconds.Only work for 'centWave'.

noise

Numeric, specify the noise level for peaking picking.Only work for 'centWave'.

prefilter

Numeric, specify the scan number threshold for prefilter.Only work for 'centWave'.

value_of_prefilter

Numeric, specify the scan abundance threshold for prefilter. Only work for 'centWave'.

fwhm

numeric specifying the full width at half maximum of matched filtration gaussian model peak. Only work for 'matchedFilter'.

steps

numeric defining the number of bins to be merged before filtration. Only work for 'matchedFilter'.

sigma

numeric specifying the standard deviation (width) of the matched filtration model peak. Only work for 'matchedFilter'.

peakBinSize

Numeric, specifying the width of the bins/slices in m/z dimension. Only work for 'matchedFilter'.

max

numeric, representing the maximum number of peaks that are expected/will be identified per slice. Only work for 'matchedFilter'.

criticalValue

criticalValue for massifquant (supported later).

consecMissedLimit

consecMissedLimit for massifquant (supported later).

unions

unions for massifquant (supported later).

checkBack

checkBack for massifquant (supported later).

withWave

withWave for massifquant (supported later). need to change.

profStep

numeric defining the bin size (in mz dimension) to be used for the profile matrix generation. Only work for 'obiwarp'.

minFraction

Numeric, specify fraction of samples in each group that contain the feature for it to be grouped.

minSamples

Numeric, specify minimum number of sample(s) in each group that contain the feature for it to be included.

maxFeatures

Numeric, specify the maximum number of features to be identified.

mzCenterFun

Character, Name of the function to calculate the m/z center of the chromatographic peak.

integrate

Integration method. For integrate = 1 peak limits are found through descent on the mexican hat filtered data, for integrate = 2 the descent is done on the real data. The latter method is more accurate but prone to noise, while the former is more robust, but less exact.

extra

Numeric, defining the maximal number of additional peaks for all samples to be assigned to a peak group (i.e. feature) for retention time correction

span

Numeric, defining the degree of smoothing (if smooth = "loess"). This parameter is passed to the internal call to loess

smooth

Character, defining the function to be used, to interpolate corrected retention times for all peak groups. Either "loess" or "linear".

family

Character, defining the method to be used for loess smoothing. Allowed values are "gaussian" and "symmetric"

fitgauss

Logical, whether or not a Gaussian should be fitted to each peak. This affects mostly the retention time position of the peak.

polarity

PeakAnnotation parameters, (Only effective for website pipeline, for local package, OptiLCMS, please use SetAnnotationParam to define the annotation parameters).

perc_fwhm

PeakAnnotation parameters, (Only effective for website pipeline, for local package, OptiLCMS, please use SetAnnotationParam to define the annotation parameters).

mz_abs_iso

PeakAnnotation parameters, (Only effective for website pipeline, for local package, OptiLCMS, please use SetAnnotationParam to define the annotation parameters).

max_charge

PeakAnnotation parameters, (Only effective for website pipeline, for local package, OptiLCMS, please use SetAnnotationParam to define the annotation parameters).

max_iso

PeakAnnotation parameters, (Only effective for website pipeline, for local package, OptiLCMS, please use SetAnnotationParam to define the annotation parameters).

corr_eic_th

PeakAnnotation parameters, (Only effective for website pipeline, for local package, OptiLCMS, please use SetAnnotationParam to define the annotation parameters).

mz_abs_add

PeakAnnotation parameters, (Only effective for website pipeline, for local package, OptiLCMS, please use SetAnnotationParam to define the annotation parameters).

adducts

PeakAnnotation parameters, (Only effective for website pipeline, for local package, OptiLCMS, please use SetAnnotationParam to define the annotation parameters).

rmConts

Logical, specify whether to exclude/remove the potential contaminations (the ones with RT range over 50% of the whole spetra).

BlankSub

Logical, to substract blanks samples or not

Value

will return a peak processing parameters' set

Author(s)

Zhiqiang Pang zhiqiang.pang@mail.mcgill.ca, Jasmine Chong jasmine.chong@mail.mcgill.ca, and Jeff Xia jeff.xia@mcgill.ca McGill University, Canada License: GNU GPL (>= 2)

References

Smith, C.A. et al. 2006. Analytical Chemistry, 78, 779-787

Examples

params <- SetPeakParam(platform = "UPLC-Q/E")

xia-lab/OptiLCMS documentation built on Nov. 16, 2024, 4:36 p.m.