"""
Functions to use GRASS 2D and 3D rasters with NumPy.
Usage:
>>> import grass.script as gs
>>> from grass.script import array as garray
>>>
>>> # We create a temporary region that is only valid in this python session
... gs.use_temp_region()
>>> gs.run_command("g.region", n=80, e=120, t=60, s=0, w=0, b=0, res=20, res3=20)
>>>
>>> # Lets create a raster map numpy array
... # based at the current region settings
... map2d_1 = garray.array()
>>>
>>> # Write some data
... for y in range(map2d_1.shape[0]):
... for x in range(map2d_1.shape[1]):
... map2d_1[y,x] = y + x
...
>>> # Lets have a look at the array
... print(map2d_1)
[[0. 1. 2. 3. 4. 5.]
[1. 2. 3. 4. 5. 6.]
[2. 3. 4. 5. 6. 7.]
[3. 4. 5. 6. 7. 8.]]
>>> # This will write the numpy array as GRASS raster map
... # with name map2d_1
... map2d_1.write(mapname="map2d_1", overwrite=True)
0
>>>
>>> # We create a new array from raster map2d_1 to modify it
... map2d_2 = garray.array(mapname="map2d_1")
>>> # Don't do map2d_2 = map2d_1 % 3
... # because: this will overwrite the internal temporary filename
... map2d_2 %= 3
>>> # Show the result
... print(map2d_2)
[[0. 1. 2. 0. 1. 2.]
[1. 2. 0. 1. 2. 0.]
[2. 0. 1. 2. 0. 1.]
[0. 1. 2. 0. 1. 2.]]
>>> # Write the result as new raster map with name map2d_2
... map2d_2.write(mapname="map2d_2", overwrite=True)
0
>>>
>>> # Here we create a 3D raster map numpy array
... # based in the current region settings
... map3d_1 = garray.array3d()
>>>
>>> # Write some data
... # Note: the 3D array has map[depth][row][column] order
... for z in range(map3d_1.shape[0]):
... for y in range(map3d_1.shape[1]):
... for x in range(map3d_1.shape[2]):
... map3d_1[z,y,x] = z + y + x
...
>>> # Lets have a look at the 3D array
... print(map3d_1)
[[[ 0. 1. 2. 3. 4. 5.]
[ 1. 2. 3. 4. 5. 6.]
[ 2. 3. 4. 5. 6. 7.]
[ 3. 4. 5. 6. 7. 8.]]
<BLANKLINE>
[[ 1. 2. 3. 4. 5. 6.]
[ 2. 3. 4. 5. 6. 7.]
[ 3. 4. 5. 6. 7. 8.]
[ 4. 5. 6. 7. 8. 9.]]
<BLANKLINE>
[[ 2. 3. 4. 5. 6. 7.]
[ 3. 4. 5. 6. 7. 8.]
[ 4. 5. 6. 7. 8. 9.]
[ 5. 6. 7. 8. 9. 10.]]]
>>> # This will write the numpy array as GRASS 3D raster map
... # with name map3d_1
... map3d_1.write(mapname="map3d_1", overwrite=True)
0
>>> # We create a new 3D array from 3D raster map3d_1 to modify it
... map3d_2 = garray.array3d(mapname="map3d_1")
>>> # Don't do map3d_2 = map3d_1 % 3
... # because: this will overwrite the internal temporary filename
... map3d_2 %= 3
>>> # Show the result
... print(map3d_2)
[[[0. 1. 2. 0. 1. 2.]
[1. 2. 0. 1. 2. 0.]
[2. 0. 1. 2. 0. 1.]
[0. 1. 2. 0. 1. 2.]]
<BLANKLINE>
[[1. 2. 0. 1. 2. 0.]
[2. 0. 1. 2. 0. 1.]
[0. 1. 2. 0. 1. 2.]
[1. 2. 0. 1. 2. 0.]]
<BLANKLINE>
[[2. 0. 1. 2. 0. 1.]
[0. 1. 2. 0. 1. 2.]
[1. 2. 0. 1. 2. 0.]
[2. 0. 1. 2. 0. 1.]]]
>>> # Write the result as new 3D raster map with name map3d_2
... map3d_2.write(mapname="map3d_2", overwrite=True)
0
(C) 2010-2021 by Glynn Clements and the GRASS Development Team
This program is free software under the GNU General Public
License (>=v2). Read the file COPYING that comes with GRASS
for details.
.. sectionauthor:: Glynn Clements
"""
import numpy as np
from .utils import try_remove
from . import core as gcore
from grass.exceptions import CalledModuleError
###############################################################################
class _tempfile:
def __init__(self, env=None):
self.filename = gcore.tempfile(env=env)
def __del__(self):
try_remove(self.filename)
###############################################################################
[docs]class array(np.memmap):
def __new__(cls, mapname=None, null=None, dtype=np.double, env=None):
"""Define new numpy array
:param cls:
:param dtype: data type (default: numpy.double)
:param env: environment
"""
reg = gcore.region(env=env)
r = reg["rows"]
c = reg["cols"]
shape = (r, c)
tempfile = _tempfile(env)
if mapname:
kind = np.dtype(dtype).kind
size = np.dtype(dtype).itemsize
if kind == "f":
flags = "f"
elif kind in "biu":
flags = "i"
else:
raise ValueError(_("Invalid kind <%s>") % kind)
if size not in {1, 2, 4, 8}:
raise ValueError(_("Invalid size <%d>") % size)
gcore.run_command(
"r.out.bin",
flags=flags,
input=mapname,
output=tempfile.filename,
bytes=size,
null=null,
quiet=True,
overwrite=True,
env=env,
)
self = np.memmap.__new__(
cls, filename=tempfile.filename, dtype=dtype, mode="r+", shape=shape
)
self.tempfile = tempfile
self.filename = tempfile.filename
self._env = env
return self
[docs] def write(self, mapname, title=None, null=None, overwrite=None, quiet=None):
"""Write array into raster map
:param str mapname: name for raster map
:param str title: title for raster map
:param null: null value
:param bool overwrite: True for overwriting existing raster maps
:return: 0 on success
:return: non-zero code on failure
"""
kind = self.dtype.kind
size = self.dtype.itemsize
if kind == "f":
if size == 4:
flags = "f"
elif size == 8:
flags = "d"
else:
raise ValueError(_("Invalid FP size <%d>") % size)
size = None
elif kind in "biu":
if size not in {1, 2, 4}:
raise ValueError(_("Invalid integer size <%d>") % size)
flags = None
else:
raise ValueError(_("Invalid kind <%s>") % kind)
# ensure all array content is written to the file
self.flush()
reg = gcore.region(env=self._env)
try:
gcore.run_command(
"r.in.bin",
flags=flags,
input=self.filename,
output=mapname,
title=title,
bytes=size,
anull=null,
overwrite=overwrite,
quiet=quiet,
north=reg["n"],
south=reg["s"],
east=reg["e"],
west=reg["w"],
rows=reg["rows"],
cols=reg["cols"],
env=self._env,
)
except CalledModuleError:
return 1
else:
return 0
###############################################################################
[docs]class array3d(np.memmap):
def __new__(cls, mapname=None, null=None, dtype=np.double, env=None):
"""Define new 3d numpy array
:param cls:
:param dtype: data type (default: numpy.double)
:param env: environment
"""
reg = gcore.region(True)
r = reg["rows3"]
c = reg["cols3"]
d = reg["depths"]
shape = (d, r, c)
tempfile = _tempfile()
if mapname:
kind = np.dtype(dtype).kind
size = np.dtype(dtype).itemsize
if kind == "f":
flags = None # default is double
elif kind in "biu":
flags = "i"
else:
raise ValueError(_("Invalid kind <%s>") % kind)
if size not in {1, 2, 4, 8}:
raise ValueError(_("Invalid size <%d>") % size)
gcore.run_command(
"r3.out.bin",
flags=flags,
input=mapname,
output=tempfile.filename,
bytes=size,
null=null,
quiet=True,
overwrite=True,
env=env,
)
self = np.memmap.__new__(
cls, filename=tempfile.filename, dtype=dtype, mode="r+", shape=shape
)
self.tempfile = tempfile
self.filename = tempfile.filename
self._env = env
return self
[docs] def write(self, mapname, null=None, overwrite=None, quiet=None):
"""Write array into 3D raster map
:param str mapname: name for 3D raster map
:param null: null value
:param bool overwrite: True for overwriting existing raster maps
:return: 0 on success
:return: non-zero code on failure
"""
kind = self.dtype.kind
size = self.dtype.itemsize
flags = None
if kind == "f":
if size not in {4, 8}:
raise ValueError(_("Invalid FP size <%d>") % size)
elif kind in "biu":
if size not in {1, 2, 4, 8}:
raise ValueError(_("Invalid integer size <%d>") % size)
flags = "i"
else:
raise ValueError(_("Invalid kind <%s>") % kind)
# ensure all array content is written to the file
self.flush()
reg = gcore.region(True, env=self._env)
try:
gcore.run_command(
"r3.in.bin",
flags=flags,
input=self.filename,
output=mapname,
bytes=size,
null=null,
overwrite=overwrite,
quiet=quiet,
north=reg["n"],
south=reg["s"],
top=reg["t"],
bottom=reg["b"],
east=reg["e"],
west=reg["w"],
depths=reg["depths"],
rows=reg["rows3"],
cols=reg["cols3"],
env=self._env,
)
except CalledModuleError:
return 1
else:
return 0
