Estimates the noise of a MassSpectrum object.
This method estimates the noise of mass spectrometry data
(represented by a MassSpectrum object).
## S4 method for signature 'MassSpectrum'
estimateNoise(object,
method=c("MAD", "SuperSmoother"),
...)object |
|
method |
used noise estimation method, one of
|
... |
arguments to be passed to |
Returns a two column matrix (first column: mass, second column: intensity) of the estimated noise.
Sebastian Gibb mail@sebastiangibb.de
## load package
library("MALDIquant")
## load example data
data("fiedler2009subset", package="MALDIquant")
## choose only the first mass spectrum
s <- fiedler2009subset[[1]]
## transform intensities
s <- transformIntensity(s, method="sqrt")
## remove baseline
s <- removeBaseline(s)
## plot spectrum
plot(s)
## estimate noise
nm <- estimateNoise(s, method="MAD")
nss <- estimateNoise(s, method="SuperSmoother")
## draw noise on the plot
lines(nm, col=2)
lines(nss, col=4)
## draw legend
legend(x="topright", lwd=1, legend=c("MAD", "SuperSmoother"),
col=c(2, 4))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.