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FTICRMS (version 0.8)

extract.pars: Extract Parameters from File

Description

Extracts the parameters in the file specified by par.file and returns them in list form.

Usage

extract.pars(par.file = "parameters.RData", root.dir = ".")

Arguments

par.file
string containing name of parameters file
root.dir
string containing directory of parameters file to be extracted from

Value

A list with the following components:
add.norm
logical; whether to normalize additively or multiplicatively on the log scale
add.par
additive parameter for "shiftedlog" or "glog" options for trans.method
align.fcn
function (and inverse) to apply to masses before (and after) applying align.method
align.method
alignment algorithm for peaks
base.dir
directory for baseline files
bhbysubj
logical; whether to look for number of large peaks by subject (i.e., combining replicates) or by spectrum
calc.all.peaks
whether to calculate all possible peaks or only sufficiently large ones
cluster.constant
parameter used in running cluster.method
cluster.method
method for determining when two peaks from different spectra are the same
cor.thresh
threshhold correlation for declaring isotopes
covariates
data frame containing covariates used in analysis
FDR
False Discovery Rate in Benjamini-Hochberg test
FTICRMS.version
Version of FTICRMS that created file
form
formula used in use.model
gengamma.quantiles
whether to use generalized gamma quantiles when calculating large peaks
halve.search
whether to use a halving-line search if step leads to smaller value of function
isotope.dist
maximum distance for declaring isotopes
lrg.dir
directory for significant peaks file
lrg.file
name of file for storing large peaks
lrg.only
whether to consider only peaks that have at least one “large” peak; i.e., identified by run.lrg.peaks
masses
specific masses to test
max.iter
convergence criterion in baseline calculation
min.spect
minimum number of spectra necessary for peak to be used in run.analysis
neg.div
negativity divisor in baseline calculation
neg.norm.by
method for negativity penalty in baseline analysis
norm.peaks
which peaks to use in normalization
norm.post.repl
logical; whether to normalize after combining replicates
normalization
type of normalization to use on spectra before statistical analysis
num.pts
number of points needed for peak fitting
oneside.min
minimum number of points on each side of local maximum for peak fitting
overwrite
whether to replace existing files with new ones
par.file
string containing name of parameters file
peak.dir
directory for peak location files
peak.method
method for locating peaks
peak.thresh
threshold for declaring large peak
pre.align
shifts to apply before running run.strong.peaks
pval.fcn
function to calculate p-values
R2.thresh
$R^2$ value needed for peak fitting
raw.dir
directory for raw data files
rel.conv.crit
whether convergence criterion should be relative to size of current baseline estimate
repl.method
how to deal with replicates
res.dir
directory for result file
res.file
name for results file
root.dir
directory for parameters file and raw data directory
sm.div
smoothness divisor in baseline calculation
sm.norm.by
method for smoothness penalty in baseline analysis
sm.ord
order of derivative to penalize in baseline analysis
sm.par
smoothing parameter for baseline calculation
subs
subset of spectra to use for analysis
subtract.base
whether to subtract calculated baseline from spectrum
tol
convergence criterion in baseline calculation
trans.method
data transformation method
use.model
what model to apply to data
zero.rm
whether to replace zeros in spectra with average of surrounding values

Details

Used by run.analysis to record all the parameter choices in an analysis for future reference.

References

Barkauskas, D.A. and D.M. Rocke. (2009a) “A general-purpose baseline estimation algorithm for spectroscopic data”. to appear in Analytica Chimica Acta. doi:10.1016/j.aca.2009.10.043

Barkauskas, D.A. et al. (2009b) “Analysis of MALDI FT-ICR mass spectrometry data: A time series approach”. Analytica Chimica Acta, 648:2, 207--214.

Barkauskas, D.A. et al. (2009c) “Detecting glycan cancer biomarkers in serum samples using MALDI FT-ICR mass spectrometry data”. Bioinformatics, 25:2, 251--257.

Benjamini, Y. and Hochberg, Y. (1995) “Controlling the false discovery rate: a practical and powerful approach to multiple testing.” J. Roy. Statist. Soc. Ser. B, 57:1, 289--300.

Xi, Y. and Rocke, D.M. (2008) “Baseline Correction for NMR Spectroscopic Metabolomics Data Analysis”. BMC Bioinformatics, 9:324.

See Also

make.par.file, run.analysis