def _get_range(self):
if self.mtype == "CELL":
self.c_range = ctypes.pointer(libraster.Range())
libraster.Rast_read_range(self.name, self.mapset, self.c_range)
else:
self.c_range = ctypes.pointer(libraster.FPRange())
libraster.Rast_read_fp_range(self.name, self.mapset, self.c_range)
def _get_range(self):
if self.mtype == 'CELL':
maprange = libraster.Range()
libraster.Rast_read_range(self.name, self.mapset,
ctypes.byref(maprange))
self._min = libgis.CELL()
self._max = libgis.CELL()
else:
maprange = libraster.FPRange()
libraster.Rast_read_fp_range(self.name, self.mapset,
ctypes.byref(maprange))
self._min = libgis.DCELL()
self._max = libgis.DCELL()
libraster.Rast_get_fp_range_min_max(ctypes.byref(maprange),
ctypes.byref(self._min),
ctypes.byref(self._max))
return self._min.value, self._max.value
def _read_raster_info(name, mapset):
"""Read the raster map info from the file system and store the content
into a dictionary
This method uses the ctypes interface to the gis and raster libraries
to read the map metadata information
:param name: The name of the map
:param mapset: The mapset of the map
:returns: The key value pairs of the map specific metadata, or None in
case of an error
"""
kvp = {}
if not libgis.G_find_raster(name, mapset):
return None
# Read the region information
region = libgis.Cell_head()
libraster.Rast_get_cellhd(name, mapset, byref(region))
kvp["north"] = region.north
kvp["south"] = region.south
kvp["east"] = region.east
kvp["west"] = region.west
kvp["nsres"] = region.ns_res
kvp["ewres"] = region.ew_res
kvp["rows"] = region.cols
kvp["cols"] = region.rows
maptype = libraster.Rast_map_type(name, mapset)
if maptype == libraster.DCELL_TYPE:
kvp["datatype"] = "DCELL"
elif maptype == libraster.FCELL_TYPE:
kvp["datatype"] = "FCELL"
elif maptype == libraster.CELL_TYPE:
kvp["datatype"] = "CELL"
# Read range
if libraster.Rast_map_is_fp(name, mapset):
range = libraster.FPRange()
libraster.Rast_init_fp_range(byref(range))
ret = libraster.Rast_read_fp_range(name, mapset, byref(range))
if ret < 0:
logging.error(_("Unable to read range file"))
return None
if ret == 2:
kvp["min"] = None
kvp["max"] = None
else:
min = libgis.DCELL()
max = libgis.DCELL()
libraster.Rast_get_fp_range_min_max(byref(range), byref(min),
byref(max))
kvp["min"] = min.value
kvp["max"] = max.value
else:
range = libraster.Range()
libraster.Rast_init_range(byref(range))
ret = libraster.Rast_read_range(name, mapset, byref(range))
if ret < 0:
logging.error(_("Unable to read range file"))
return None
if ret == 2:
kvp["min"] = None
kvp["max"] = None
else:
min = libgis.CELL()
max = libgis.CELL()
libraster.Rast_get_range_min_max(byref(range), byref(min),
byref(max))
kvp["min"] = min.value
kvp["max"] = max.value
return kvp