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Source code for script.raster

"""
Raster related functions to be used in Python scripts.

Usage:

::

    from grass.script import raster as grass
    grass.raster_history(map)


(C) 2008-2011 by 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
.. sectionauthor:: Martin Landa <landa.martin gmail.com>
"""
from __future__ import absolute_import

import os
import sys
import string
import time

from .core import *
from grass.exceptions import CalledModuleError
from .utils import float_or_dms, parse_key_val


if sys.version_info.major == 3:
    unicode = str


[docs]def raster_history(map): """Set the command history for a raster map to the command used to invoke the script (interface to `r.support`). :param str map: map name :return: True on success :return: False on failure """ current_mapset = gisenv()['MAPSET'] if find_file(name=map)['mapset'] == current_mapset: run_command('r.support', map=map, history=os.environ['CMDLINE']) return True warning(_("Unable to write history for <%(map)s>. " "Raster map <%(map)s> not found in current mapset." % { 'map': map, 'map': map})) return False
[docs]def raster_info(map): """Return information about a raster map (interface to `r.info -gre`). Example: >>> raster_info('elevation') # doctest: +ELLIPSIS {'creator': '"helena"', 'cols': '1500' ... 'south': 215000.0} :param str map: map name :return: parsed raster info """ def float_or_null(s): if s == 'NULL': return None else: return float(s) s = read_command('r.info', flags='gre', map=map) kv = parse_key_val(s) for k in ['min', 'max']: kv[k] = float_or_null(kv[k]) for k in ['north', 'south', 'east', 'west']: kv[k] = float(kv[k]) for k in ['nsres', 'ewres']: kv[k] = float_or_dms(kv[k]) return kv
[docs]def mapcalc(exp, quiet=False, verbose=False, overwrite=False, seed=None, env=None, **kwargs): """Interface to r.mapcalc. :param str exp: expression :param bool quiet: True to run quietly (<tt>--q</tt>) :param bool verbose: True to run verbosely (<tt>--v</tt>) :param bool overwrite: True to enable overwriting the output (<tt>--o</tt>) :param seed: an integer used to seed the random-number generator for the rand() function, or 'auto' to generate a random seed :param dict env: dictionary of environment variables for child process :param kwargs: """ if seed == 'auto': seed = hash((os.getpid(), time.time())) % (2**32) t = string.Template(exp) e = t.substitute(**kwargs) try: write_command('r.mapcalc', file='-', stdin=e, env=env, seed=seed, quiet=quiet, verbose=verbose, overwrite=overwrite) except CalledModuleError: fatal(_("An error occurred while running r.mapcalc" " with expression: %s") % e)
[docs]def mapcalc_start(exp, quiet=False, verbose=False, overwrite=False, seed=None, env=None, **kwargs): """Interface to r.mapcalc, doesn't wait for it to finish, returns Popen object. >>> output = 'newele' >>> input = 'elevation' >>> expr1 = '"%s" = "%s" * 10' % (output, input) >>> expr2 = '...' # etc. >>> # launch the jobs: >>> p1 = mapcalc_start(expr1) >>> p2 = mapcalc_start(expr2) ... >>> # wait for them to finish: >>> p1.wait() 0 >>> p2.wait() 1 >>> run_command('g.remove', flags='f', type='raster', name=output) :param str exp: expression :param bool quiet: True to run quietly (<tt>--q</tt>) :param bool verbose: True to run verbosely (<tt>--v</tt>) :param bool overwrite: True to enable overwriting the output (<tt>--o</tt>) :param seed: an integer used to seed the random-number generator for the rand() function, or 'auto' to generate a random seed :param dict env: dictionary of environment variables for child process :param kwargs: :return: Popen object """ if seed == 'auto': seed = hash((os.getpid(), time.time())) % (2**32) t = string.Template(exp) e = t.substitute(**kwargs) p = feed_command('r.mapcalc', file='-', env=env, seed=seed, quiet=quiet, verbose=verbose, overwrite=overwrite) p.stdin.write(e) p.stdin.close() return p
[docs]def raster_what(map, coord, env=None, localized=False): """Interface to r.what >>> raster_what('elevation', [[640000, 228000]]) [{'elevation': {'color': '255:214:000', 'label': '', 'value': '102.479'}}] :param str map: the map name :param list coord: a list of list containing all the point that you want query :param env: """ if isinstance(map, (bytes, unicode)): map_list = [map] else: map_list = map coord_list = list() if isinstance(coord, tuple): coord_list.append('%f,%f' % (coord[0], coord[1])) else: for e, n in coord: coord_list.append('%f,%f' % (e, n)) sep = '|' # separator '|' not included in command # because | is causing problems on Windows # change separator? ret = read_command('r.what', flags='rf', map=','.join(map_list), coordinates=','.join(coord_list), null=_("No data"), quiet=True, env=env) data = list() if not ret: return data if localized: labels = (_("value"), _("label"), _("color")) else: labels = ('value', 'label', 'color') for item in ret.splitlines(): line = item.split(sep)[3:] for i, map_name in enumerate(map_list): tmp_dict = {} tmp_dict[map_name] = {} for j in range(len(labels)): tmp_dict[map_name][labels[j]] = line[i*len(labels)+j] data.append(tmp_dict) return data

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