Geografic-Information-System/lib/python/pygrass/functions.py

# -*- coding: utf-8 -*-
"""
Created on Tue Jun 26 12:38:48 2012

@author: pietro
"""

import fnmatch

import grass.lib.gis as libgis
import grass.lib.raster as libraster
from grass.script import core as grasscore

from grass.pygrass.errors import GrassError
from grass.pygrass.gis.region import Region


def looking(obj, filter_string):
    """
    >>> import grass.lib.vector as libvect
    >>> sorted(looking(libvect, '*by_box*'))  # doctest: +NORMALIZE_WHITESPACE
    ['Vect_select_areas_by_box', 'Vect_select_isles_by_box',
     'Vect_select_lines_by_box', 'Vect_select_nodes_by_box']

    """
    word_list = dir(obj)
    word_list.sort()
    return fnmatch.filter(word_list, filter_string)


def remove(oldname, maptype):
    """Remove a map"""
    grasscore.run_command('g.remove', **{maptype: '{old}'.format(old=oldname)})


def rename(oldname, newname, maptype):
    """Rename a map"""
    grasscore.run_command('g.rename',
                          **{maptype: '{old},{new}'.format(old=oldname,
                                                           new=newname), })


def copy(existingmap, newmap, maptype):
    """Copy a map

    >>> copy('census', 'mycensus', 'vect')
    >>> rename('mycensus', 'mynewcensus', 'vect')
    >>> remove('mynewcensus', 'vect')

    """
    grasscore.run_command('g.copy',
                          **{maptype: '{old},{new}'.format(old=existingmap,
                                                           new=newmap), })


def getenv(env):
    """Return the current grass environment variables ::

        >>> getenv("MAPSET")
        'user1'

    """
    return libgis.G__getenv(env)


def get_mapset_raster(mapname, mapset=''):
    """Return the mapset of the raster map ::

    >>> get_mapset_raster('elevation')
    'PERMANENT'

    """
    return libgis.G_find_raster(mapname, '')


def get_mapset_vector(mapname, mapset=''):
    """Return the mapset of the vector map ::

    >>> get_mapset_vector('census')
    'PERMANENT'

    """
    return libgis.G_find_vector(mapname, '')


def is_clean_name(name):
    """Return if the name is valid ::

    >>> is_clean_name('census')
    True
    >>> is_clean_name('0census')
    False
    >>> is_clean_name('census&')
    False

    """
    if name[0].isdigit():
        return False
    for char in ' @#^?°,;%&/':
        if name.find(char) != -1:
            return False
    return True


def coor2pixel((east, north), region):
    """Convert coordinates into a pixel row and col ::

        >>> reg = Region()
        >>> coor2pixel((reg.west, reg.north), reg)
        (0.0, 0.0)
        >>> coor2pixel((reg.east, reg.south), reg) == (reg.rows, reg.cols)
        True
    """
    return (libraster.Rast_northing_to_row(north, region.c_region),
            libraster.Rast_easting_to_col(east, region.c_region))


def pixel2coor((col, row), region):
    """Convert row and col of a pixel into a coordinates ::

        >>> reg = Region()
        >>> pixel2coor((0, 0), reg) == (reg.north, reg.west)
        True
        >>> pixel2coor((reg.cols, reg.rows), reg) == (reg.south, reg.east)
        True
    """
    return (libraster.Rast_row_to_northing(row, region.c_region),
            libraster.Rast_col_to_easting(col, region.c_region))


def get_raster_for_points(point, raster):
    """Query a raster map for each point feature of a vector

    Parameters
    -------------

    point: point vector object

    raster: raster object
    """
    reg = Region()
    if not point.is_open():
        point.open()
    if point.num_primitive_of('point') == 0:
        raise GrassError(_("Vector doesn't contain points"))
    values = [raster.get_value(poi.coords, reg) for poi in point.viter('point')]
    return values