GRASS GIS logo

Source code for script.array

"""
Functions to use GRASS 2D and 3D rasters with NumPy.

Usage:

>>> from __future__ import print_function
>>> import grass.script as gscript
>>> from grass.script import array as garray
>>>
>>> # We create a temporary region that is only valid in this python session
... gscript.use_temp_region()
>>> gscript.run_command("g.region", n=80, e=120, t=60, s=0, w=0, b=0, res=20, res3=20)
0
>>>
>>> # 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) 2010-2012 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
"""

from __future__ import absolute_import
import sys

import numpy

from .utils import try_remove
from . import core as gcore
from grass.exceptions import CalledModuleError


###############################################################################

class _tempfile(object):
    def __init__(self):
        self.filename = gcore.tempfile()

    def __del__(self):
        try_remove(self.filename)

###############################################################################

[docs]class array(numpy.memmap): def __new__(cls, mapname=None, null=None, dtype=numpy.double): """Define new numpy array :param cls: :param dtype: data type (default: numpy.double) """ reg = gcore.region() r = reg['rows'] c = reg['cols'] shape = (r, c) tempfile = _tempfile() 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) self = numpy.memmap.__new__( cls, filename=tempfile.filename, dtype=dtype, mode='r+', shape=shape) self.tempfile = tempfile self.filename = tempfile.filename return self
[docs] def read(self, mapname, null=None): """Read raster map into array :param str mapname: name of raster map to be read :param null: null value :return: 0 on success :return: non-zero code on failure .. deprecated:: 7.1 Instead reading the map after creating the array, pass the map name in the array constructor. """ if sys.platform == 'win32': gcore.warning(_("grass.script.array.read is deprecated and does not" " work on MS Windows, pass raster name in the constructor")) kind = self.dtype.kind size = self.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) try: gcore.run_command( 'r.out.bin', flags=flags, input=mapname, output=self.filename, bytes=size, null=null, quiet=True, overwrite=True) except CalledModuleError: return 1 else: return 0
[docs] def write(self, mapname, title=None, null=None, overwrite=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 overwritting 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) reg = gcore.region() try: gcore.run_command( 'r.in.bin', flags=flags, input=self.filename, output=mapname, title=title, bytes=size, anull=null, overwrite=overwrite, north=reg['n'], south=reg['s'], east=reg['e'], west=reg['w'], rows=reg['rows'], cols=reg['cols']) except CalledModuleError: return 1 else: return 0 ###############################################################################
[docs]class array3d(numpy.memmap): def __new__(cls, mapname=None, null=None, dtype=numpy.double): """Define new 3d numpy array :param cls: :param dtype: data type (default: numpy.double) """ 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) self = numpy.memmap.__new__( cls, filename=tempfile.filename, dtype=dtype, mode='r+', shape=shape) self.tempfile = tempfile self.filename = tempfile.filename return self
[docs] def read(self, mapname, null=None): """Read 3D raster map into array :param str mapname: name of 3D raster map to be read :param null: null value :return: 0 on success :return: non-zero code on failure .. deprecated:: 7.1 Instead reading the map after creating the array, pass the map name in the array constructor. """ if sys.platform == 'win32': gcore.warning(_("grass.script.array3d.read is deprecated and does not" " work on MS Windows, pass 3D raster name in the constructor")) kind = self.dtype.kind size = self.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) try: gcore.run_command( 'r3.out.bin', flags=flags, input=mapname, output=self.filename, bytes=size, null=null, quiet=True, overwrite=True) except CalledModuleError: return 1 else: return 0
[docs] def write(self, mapname, null=None, overwrite=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) reg = gcore.region(True) try: gcore.run_command( 'r3.in.bin', flags=flags, input=self.filename, output=mapname, bytes=size, null=null, overwrite=overwrite, 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']) except CalledModuleError: return 1 else: return 0

Help Index | Topics Index | Keywords Index | Full Index

© 2003-2017 GRASS Development Team, GRASS GIS 7.5.svn Reference Manual