R/NIRsoil.R

In l-ramirez-lopez/prospectr: Miscellaneous Functions for Processing and Sample Selection of Spectroscopic Data

#' @docType data
#' @name NIRsoil
#' @aliases NIRsoil
#' @title NIRSoil
#' @format A `data.frame` of 825 observations and 5 variables (where the spectral
#' data is embedded in one variable `NIRSoil$spc`).
#' @usage
#' data(NIRsoil)
#' @description
#' Soil spectral library of the \sQuote{Chimiometrie 2006} challenge.
#' The database contains absorbance spectra of dried and sieved soil samples
#' measured between 1100 nm and 2498 nm at 2 nm interval. The soil samples come
#' from agricultural fields collected from all over the Walloon region in Belgium.
#' Three parameters are associated with the spectral library: Nt (Total Nitrogen
#' in g/Kg of dry soil), CEC (Cation Exchange Capacity in meq/100 g of dry soil)
#' and Ciso (Carbon in g/100 g of dry soil). Carbon content has been measured
#' following the ISO14235 method.
#' @details
#' The dataset includes 618 training and 207 test samples with 5 variables:
#' \itemize{
#'   \item{Nt (Total Nitrogen).}
#'   \item{Ciso (Carbon).}
#'   \item{CEC (Cation Exchange Capacity).}
#'   \item{train (binary vector indicating training (1) and validation (0) samples).}
#'   \item{and spc (a matrix of spectral NIR absorbance values, where the band/wavelength positions are stored as `colnames`).}
#'  }
#' Nt, Ciso and CEC have respectively 22 \%, 11 \% and 46 \% of the observations
#' with missing values.
#' @source Pierre Dardenne from Walloon Agricultural Research Centre, Belgium.
#' @references
#' Fernandez Pierna, J.A., and Dardenne, P., 2008. Soil parameter quantification
#' by NIRS as a Chemometric challenge at 'Chimiometrie 2006'. Chemometrics and
#' Intelligent Laboratory Systems 91, 94-98.
#' @keywords datasets
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