Source code for pygrass.raster.buffer
from grass.pygrass.raster.raster_type import TYPE as RTYPE
import ctypes
import numpy as np
_CELL = ("int", "int0", "int8", "int16", "int32", "int64")
CELL = tuple([getattr(np, attr) for attr in _CELL if hasattr(np, attr)])
_FCELL = "float", "float16", "float32"
FCELL = tuple([getattr(np, attr) for attr in _FCELL if hasattr(np, attr)])
_DCELL = "float64", "float128"
DCELL = tuple([getattr(np, attr) for attr in _DCELL if hasattr(np, attr)])
[docs]class Buffer(np.ndarray):
"""shape, mtype='FCELL', buffer=None, offset=0,
strides=None, order=None
"""
@property
def mtype(self):
if self.dtype in CELL:
return "CELL"
elif self.dtype in FCELL:
return "FCELL"
elif self.dtype in DCELL:
return DCELL
else:
err = "Raster type: %r not supported by GRASS."
raise TypeError(err % self.dtype)
def __new__(
cls, shape, mtype="FCELL", buffer=None, offset=0, strides=None, order=None
):
obj = np.ndarray.__new__(
cls, shape, RTYPE[mtype]["numpy"], buffer, offset, strides, order
)
obj.pointer_type = ctypes.POINTER(RTYPE[mtype]["ctypes"])
obj.p = obj.ctypes.data_as(obj.pointer_type)
return obj
def __array_finalize__(self, obj):
if obj is None:
return
self.pointer_type = getattr(obj, "pointer_type", None)
self.p = getattr(obj, "p", None)
def __array_wrap__(self, out_arr, context=None):
"""See:
http://docs.scipy.org/doc/numpy/user/
basics.subclassing.html#array-wrap-for-ufuncs"""
if out_arr.dtype == np.bool:
# there is not support for boolean maps, so convert into integer
out_arr = out_arr.astype(np.int32)
out_arr.p = out_arr.ctypes.data_as(out_arr.pointer_type)
return np.ndarray.__array_wrap__(self, out_arr, context)