erosing.R

#This file is part of ChiVO, the Chilean Virtual Observatory
#A project sponsored by FONDEF (D11I1060)
#Copyright (C) 2015 Universidad Tecnica Federico Santa Maria Mauricio Solar
#                                                            Marcelo Mendoza
#                   Universidad de Chile                     Diego Mardones
#                   Pontificia Universidad Catolica          Karim Pichara
#                   Universidad de Concepcion                Ricardo Contreras
#                   Universidad de Santiago                  Victor Parada
#
# 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 (at your option) 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.

#
erosing <- function(boxing) {
  n = length(boxing)
  blocking <- array(0.0, dim=c(n))
  for (i in 2:(n-1)){
    blocking[i] <- boxing[i]
  if ((boxing[i-1]==0) & (boxing[i]==1) & (boxing[i+1]==0))
    blocking[i] <- 0
  }
  boxing <- array(0.0, dim=c(n))
  boxing <- blocking
  for (i in 2:(n-1)){
    if ((blocking[i-1]==0) & (blocking[i]==1))
      boxing[i-1] <- 1
    if ((blocking[i]==1) & (blocking[i+1]==0))
      boxing[i+1] <- 1
  }
  return(boxing)
}