File: raster.py

package info (click to toggle)
grass 7.2.0-2
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 135,976 kB
  • ctags: 44,148
  • sloc: ansic: 410,300; python: 166,939; cpp: 34,819; sh: 9,358; makefile: 6,618; xml: 3,551; sql: 769; lex: 519; yacc: 450; asm: 387; perl: 282; sed: 17; objc: 7
file content (212 lines) | stat: -rw-r--r-- 6,127 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
"""
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 string
import time

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


try:
    from builtins import unicode
    bytes = str
except ImportError:
    # python3
    unicode = str


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


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


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"))


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


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