R/MGC_Random.R

In mhahsler/stream: Infrastructure for Data Stream Mining

#######################################################################
# Moving Generator -  Infrastructure for Moving Streams
# Copyright (C) 2013 Michael Hahsler, Matthew Bolanos, John Forrest
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

MGC_Random_refClass <- setRefClass(
  "MGC_Random",
  fields = list(
    start = "numeric",
    current = "numeric",
    parameter = "numeric",
    density = "numeric",
    lastUpdate = "numeric",
    randomness = "numeric",
    dimension = "numeric",
    shape = "function"
  ),

  methods = list(
    initialize = function(s, p, d, r, sha) {
      start  <<- s
      current <<- s
      density <<- d
      parameter <<- p
      randomness <<- r
      lastUpdate <<- 1
      shape <<- sha
      dimension <<- length(s)
      .self
    }

  ),
)

MGC_Random_refClass$methods(
  get_attributes = function(time, attributes = NULL) {
    att <-
      list(density = density,
        parameter = parameter,
        randomness = randomness)
    if (!is.null(attributes))
      att <- att[attributes]
    att
  },

  get_points = function(time) {
    if (time == 1)
      current <<- start
    if (floor(time) > lastUpdate) {
      current <<-
        current + runif(length(current),-randomness, randomness)
      lastUpdate <<- floor(time)
    }

    shape(center = current, parameter = parameter)
  }
)

#' @rdname MGC
#' @export
MGC_Random <-
  function(density,
    center,
    parameter,
    randomness = 1,
    shape = Shape_Gaussian) {

    structure(
      list(
        description = "Random Moving Generator Cluster",
        RObj = MGC_Random_refClass$new(center, parameter, density, randomness, shape)
      ),
      class = c("MGC_Random", "MGC")
    )
  }