def __new__(cls,
name,
mapset="",
mtype='CELL',
mode='r+',
overwrite=False):
reg = Region()
shape = (reg.rows, reg.cols)
mapset = libgis.G_find_raster(name, mapset)
gtype = None
if mapset:
# map exist, set the map type
gtype = libraster.Rast_map_type(name, mapset)
mtype = RTYPE_STR[gtype]
filename = grasscore.tempfile()
obj = np.memmap.__new__(cls,
filename=filename,
dtype=RTYPE[mtype]['numpy'],
mode=mode,
shape=shape)
obj.mtype = mtype.upper()
obj.gtype = gtype if gtype else RTYPE[mtype]['grass type']
obj._rows = reg.rows
obj._cols = reg.cols
obj.filename = filename
obj._name = name
obj.mapset = mapset
obj.reg = reg
obj.overwrite = overwrite
return obj
def open_band_files(self):
for n in xrange(6):
self.data_type.append(
raster.Rast_map_type(self.name[n], self.mapset))
if self.data_type[n] == 0:
ptype = POINTER(c_int)
elif self.data_type[n] == 1:
ptype = POINTER(c_float)
elif self.data_type[n] == 2:
ptype = POINTER(c_double)
self.infd.append(raster.Rast_open_old(self.name[n], self.mapset))
self.Bandbuf.append(raster.Rast_allocate_buf(self.data_type[n]))
self.Bandbuf[n] = cast(c_void_p(self.Bandbuf[n]), ptype)
def mtype(self):
return RTYPE_STR[libraster.Rast_map_type(self.name, self.mapset)]
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
