R/SOS-methods-coercion.R

In 52North/sos4R: Client for OGC Sensor Observation Services

############################################################################## #
# Copyright (C) 2019 by 52 North                                               #
# Initiative for Geospatial Open Source Software GmbH                          #
#                                                                              #
# Contact: Andreas Wytzisk                                                     #
# 52 North Initiative for Geospatial Open Source Software GmbH                 #
# Martin-Luther-King-Weg 24                                                    #
# 48155 Muenster, Germany                                                      #
# info@52north.org                                                             #
#                                                                              #
# This program is free software; you can redistribute and/or modify it under   #
# the terms of the GNU General Public License version 2 as published by the    #
# Free Software Foundation.                                                    #
#                                                                              #
# This program is distributed WITHOUT ANY WARRANTY; even without 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 (see gpl-2.0.txt). If not, write to the Free Software           #
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA or #
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#                                                                              #
# Author: Daniel Nuest (daniel.nuest@uni-muenster.de)                          #
# Created: 2011-02-09                                                          #
# Project: sos4R - https://github.com/52North/sos4R                            #
#                                                                              #
############################################################################## #

#
#
#
as.SpatialPolygons.SosObservationOffering = function(from) {
  # create bounding polygon from offering bounding box
  bbox <- sosBoundedBy(from, bbox = TRUE)
  llat <- bbox["coords.lat","min"]
  llon <- bbox["coords.lon","min"]
  ulat <- bbox["coords.lat","max"]
  ulon <- bbox["coords.lon","max"]

  crs <- sosGetCRS(from)
  if (is.null(crs)) {
    warning(paste("Cannot coerce offering", sosId(from), "to SpatialPolygons -- no CRS given."))
    return(NULL)
  }

  # beginning at lower left corner:
  poly <- sp::Polygon(cbind(c(llon, llon, ulon, ulon, llon),
                         c(llat, ulat, ulat, llat, llat)))
  spPoly <- sp::SpatialPolygons(list(
    sp::Polygons(list(poly), sosName(from))),
    proj4string = crs)

  return(spPoly)
}
setAs(from = "SosObservationOffering", to = "SpatialPolygons",
      function(from) {
        as.SpatialPolygons.SosObservationOffering(from)
      }
)
setAs(from = "SosObservationOffering", to = "Spatial",
      function(from) {
        as.SpatialPolygons.SosObservationOffering(from)
      }
)