clean-methods {MSnbase} | R Documentation

## Clean 'MSnExp', 'Spectrum' or 'Chromatogram' instances

### Description

This method cleans out individual spectra (`Spectrum` instances), chromatograms (`Chromatogram` instances) or whole experiments (`MSnExp` instances) of 0-intensity peaks. Unless `all` is set to `FALSE`, original 0-intensity values are retained only around peaks. If more than two 0's were separating two peaks, only the first and last ones, those directly adjacent to the peak ranges are kept. If two peaks are separated by only one 0-intensity value, it is retained. An illustrative example is shown below.

### Methods

`signature(object = "MSnExp", all = "logical", verbose = "logical")`

  Cleans all spectra in `MSnExp` object. Displays a control bar if verbose set to `TRUE` (default). Returns a cleaned `MSnExp` instance.

`signature(object = "Spectrum", all = "logical", msLevel. = "numeric")`

  Cleans the `Spectrum` object. Returns a cleaned `Spectrum` instance. If `all = TRUE`, then all zeros are removed. `msLevel.` defines the level of the spectrum, and if `msLevel(object) != msLevel.`, cleaning is ignored. Only relevant when called from `OnDiskMSnExp` and is only relevant for developers.

`signature(object = "Chromatogram", all = "logical", na.rm = "logical")`

  Cleans the `Chromatogram` instance and returns a cleaned `Chromatogram` object. If `na.rm` is `TRUE` (default is `FALSE`) all `NA` intensities are removed before cleaning the chromatogram.

### Author(s)

Laurent Gatto <lg390@cam.ac.uk>

### See Also

`removePeaks` and `trimMz` for other spectra processing methods.

### Examples

    int <- c(1,0,0,0,0,0,0,0,1,1,1,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,1,0,0,0)
    sp1 <- new("Spectrum2",
               intensity=int,
               mz=1:length(int))
    sp2 <- clean(sp1) ## default is all=FALSE
    intensity(sp1)
    intensity(sp2)
    intensity(clean(sp1, all = TRUE))

    mz(sp1)
    mz(sp2)
    mz(clean(sp1, all = TRUE))

    data(itraqdata)
    itraqdata2 <- clean(itraqdata)
    sum(peaksCount(itraqdata))
    sum(peaksCount(itraqdata2))
    processingData(itraqdata2)

    ## Create a simple Chromatogram object
    chr <- Chromatogram(rtime = 1:12,
                        intensity = c(0, 0, 20, 0, 0, 0, 123, 124343, 3432, 0, 0, 0))

    ## Remove 0-intensity values keeping those adjacent to peaks
    chr <- clean(chr)
    intensity(chr)

    ## Remove all 0-intensity values
    chr <- clean(chr, all = TRUE)
    intensity(chr)

    ## Clean a Chromatogram with NAs.
    chr <- Chromatogram(rtime = 1:12,
                        intensity = c(0, 0, 20, NA, NA, 0, 123, 124343, 3432, 0, 0, 0))
    chr <- clean(chr, all = FALSE, na.rm = TRUE)
    intensity(chr)

[Package MSnbase version 2.18.0 Index]