Source code for script.array

"""
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

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(numpy.memmap): def __new__(cls, mapname=None, null=None, dtype=numpy.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 = numpy.dtype(dtype).kind size = numpy.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 = numpy.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(numpy.memmap): def __new__(cls, mapname=None, null=None, dtype=numpy.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 = numpy.dtype(dtype).kind size = numpy.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 = numpy.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 != 4 and size != 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