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prospectr
provides various utilities for pre--processing and sample selection of visible and near infrared spectral data with R. While similar functions are available in other packages, like signal
, the functions in this package works indifferently for data.frame
, matrix
and vector
inputs. Besides, several functions are optimized for speed and use C++ code through the Rcpp
and RcppArmadillo
packages.
A vignette gives an overview of the main functionalities of the package. Just type vignette("prospectr-intro")
in the console to access it. Currently, the following preprocessing functions are available:
continuumRemoval
: continuum-removed absorbance or reflectance values
savitzkyGolay
: Savitzky-Golay filter (smoothing and derivatives)
gapDer
: gap-segment derivative
movav
: moving average
standardNormalVariate
: standard normal variate (snv)
detrend
: detrend normalization
binning
: average in column--wise subsets
resample
: resample a signal to new coordinates by linear or spline interpolation
resample2
: resample a signal to new coordinates using FWHM values
blockScale
: block scaling
blockNorm
: sum of squares block weighting
The selection of samples/observations for calibration of vis-NIR data can be achieved with one of the following functions
kenStone
: CADEX (Kennard--Stone) algorithm
duplex
: DUPLEX algorithm
naes
: k-means sampling
shenkWest
: SELECT algorithm
puchwein
: Puchwein sampling
honigs
: Unique-sample selection by spectral subtraction
Other useful functions are also available:
readASD
: read binary or text files from an ASD instrument (Indico Pro format)
spliceCorrection
: correct spectra for steps at the splice of detectors in an ASD FieldSpec Pro
cochranTest
: detects replicate outliers with the Cochran C test
You can send an email to the package maintainer ([email protected]) or create an issue on github. To install the development version of prospectr
, simply install devtools
from CRAN then run install_github("prospectr","antoinestevens")
.