MS Data Analysis

Description Usage Arguments Value Author(s) See Also

The methods listed on this page are XCMSnExp methods inherited from its parent, the OnDiskMSnExp class from the MSnbase package, that alter the raw data or are related to data subsetting. Thus calling any of these methods causes all xcms pre-processing results to be removed from the XCMSnExp object to ensure its data integrity.

bin: allows to bin spectra. See bin documentation in the MSnbase package for more details and examples.

clean: removes unused 0 intensity data points. See clean documentation in the MSnbase package for details and examples.

filterAcquisitionNum: filters the XCMSnExp object keeping only spectra with the provided acquisition numbers. See filterAcquisitionNum for details and examples.

The normalize method performs basic normalization of spectra intensities. See normalize documentation in the MSnbase package for details and examples.

The pickPeaks method performs peak picking. See pickPeaks documentation for details and examples.

The removePeaks method removes mass peaks (intensities) lower than a threshold. Note that these peaks refer to mass peaks, which are different to the chromatographic peaks detected and analyzed in a metabolomics experiment! See removePeaks documentation for details and examples.

The smooth method smooths spectra. See smooth documentation in MSnbase for details and examples.

## S4 method for signature 'XCMSnExp'
bin(object, binSize = 1L, msLevel.)

## S4 method for signature 'XCMSnExp'
clean(object, all = FALSE, verbose = FALSE,
  msLevel.)

## S4 method for signature 'XCMSnExp'
filterAcquisitionNum(object, n, file)

## S4 method for signature 'XCMSnExp'
normalize(object, method = c("max", "sum"), ...)

## S4 method for signature 'XCMSnExp'
pickPeaks(object, halfWindowSize = 3L,
  method = c("MAD", "SuperSmoother"), SNR = 0L, ...)

## S4 method for signature 'XCMSnExp'
removePeaks(object, t = "min", verbose = FALSE,
  msLevel.)

## S4 method for signature 'XCMSnExp'
smooth(x, method = c("SavitzkyGolay",
  "MovingAverage"), halfWindowSize = 2L, verbose = FALSE, ...)

`object`	`XCMSnExp` or `OnDiskMSnExp` object.
`binSize`	`numeric(1)` defining the size of a bin (in Dalton).
`msLevel.`	For `bin`, `clean`, `filterMsLevel`, `removePeaks`: `numeric(1)` defining the MS level(s) to which operations should be applied or to which the object should be subsetted.
`all`	For `clean`: `logical(1)`, if `TRUE` all zeros are removed.
`verbose`	`logical(1)` whether progress information should be displayed.
`n`	For `filterAcquisitionNum`: `integer` defining the acquisition numbers of the spectra to which the data set should be sub-setted.
`file`	For `filterAcquisitionNum`: `integer` defining the file index within the object to subset the object by file.
`method`	For `normalize`: `character(1)` specifying the normalization method. See `normalize` in the `MSnbase` package for details. For `pickPeaks`: `character(1)` defining the method. See `pickPeaks` for options. For `smooth`: `character(1)` defining the method. See `smooth` in the `MSnbase` package for options and details.
`...`	Optional additional arguments.
`halfWindowSize`	For `pickPeaks` and `smooth`: `integer(1)` defining the window size for the peak picking. See `pickPeaks` and `smooth` in the `MSnbase` package for details and options.
`SNR`	For `pickPeaks`: `numeric(1)` defining the signal to noise ratio to be considered. See `pickPeaks` documentation for details.
`t`	For `removePeaks`: either a `numeric(1)` or `"min"` defining the threshold (method) to be used. See `removePeaks` for details.
`x`	`XCMSnExp` or `OnDiskMSnExp` object.

For all methods: a XCMSnExp object.

Johannes Rainer

XCMSnExp-filter for methods to filter and subset XCMSnExp objects. XCMSnExp for base class documentation. OnDiskMSnExp for the documentation of the parent class.

anupbharade09/xcms_test documentation built on May 14, 2019, 4:07 a.m.