R/methodDtwclust.R

In latrend: A Framework for Clustering Longitudinal Data

#' @include method.R

#' @name interface-dtwclust
#' @rdname interface-dtwclust
#' @title dtwclust interface
#' @seealso [lcMethodDtwclust] \link[dtwclust]{dtwclust-package}
#' @keywords internal
NULL

setClass('lcMethodDtwclust', contains = 'lcMethod')

#' @export
#' @title Specify time series clustering via dtwclust
#' @param response The name of the response variable.
#' @param time The name of the time variable.
#' @param id The name of the trajectory identifier variable.
#' @param nClusters Number of clusters.
#' @param ... Arguments passed to [dtwclust::tsclust].
#' The following arguments are ignored: series, k, trace.
#' @examples
#' data(latrendData)
#'
#' if (require("dtwclust")) {
#'   method <- lcMethodDtwclust("Y", id = "Id", time = "Time", nClusters = 3)
#'   model <- latrend(method, latrendData)
#' }
#' @family lcMethod implementations
#' @references
#' \insertRef{sardaespinosa2019time}{latrend}
lcMethodDtwclust = function(
  response,
  time = getOption('latrend.time'),
  id = getOption('latrend.id'),
  nClusters = 2,
  ...
) {
  mc = match.call.all()
  mc$Class = 'lcMethodDtwclust'
  do.call(new, as.list(mc))

}

#' @rdname interface-dtwclust
setMethod('getArgumentDefaults', 'lcMethodDtwclust', function(object) {
  .loadOptionalPackage('dtwclust')
  c(
    formals(lcMethodDtwclust),
    formals(dtwclust::tsclust),
    callNextMethod()
  )
})

#' @rdname interface-dtwclust
setMethod('getArgumentExclusions', 'lcMethodDtwclust', function(object) {
  union(
    callNextMethod(),
    c('series', 'k', 'trace')
  )
})

#' @rdname interface-dtwclust
#' @inheritParams getName
setMethod('getName', 'lcMethodDtwclust', function(object) paste0('time series clustering with ', object$distance, '-dissimilarity'))

#' @rdname interface-dtwclust
setMethod('getShortName', 'lcMethodDtwclust', function(object) paste0('diss-', object$distance))

#' @rdname interface-dtwclust
setMethod('preFit', 'lcMethodDtwclust', function(method, data, envir, verbose, ...) {
  e = new.env()
  # convert data to list format
  e$seriesList = split(data, data[[idVariable(method)]]) %>%
    lapply('[[', responseVariable(method))
  return(e)
})

#' @rdname interface-dtwclust
#' @inheritParams fit
setMethod('fit', 'lcMethodDtwclust', function(method, data, envir, verbose, ...) {
  args = as.list(method)
  args$series = envir$seriesList
  args$k = method$nClusters
  args$trace = as.logical(verbose)

  cat(verbose, 'Running tsclust()...', level = verboseLevels$finest)
  tsClusters = do.call(dtwclust::tsclust, args)

  new(
    'lcModelDtwclust',
    method = method,
    data = data,
    model = tsClusters,
    clusterNames = make.clusterNames(method$nClusters)
  )
})