# -*- coding: utf-8 -*- """ Created on Tue Mar 19 11:09:30 2013 @author: pietro """ import grass.lib.vector as libvect from grass.pygrass.errors import must_be_open from basic import Ilist from geometry import read_line, Isle, Area class Finder(object): """Find the geomtry features of a vector map that are close to a point. :: >>> from grass.pygrass.vector import VectorTopo >>> zipcodes = VectorTopo('zipcodes', 'PERMANENT') >>> schools = VectorTopo('schools', 'PERMANENT') >>> zipcodes.open('r') >>> schools.open('r') >>> result = [] >>> for school in schools: ... zipcode = zipcodes.find.area(school) ... result.append((school.attrs['NAMESHORT'], ... zipcode.attrs['ZIPCODE'])) ... >>> result[0] (u'SWIFT CREEK', u'RALEIGH 27606') >>> result[1] (u'BRIARCLIFF', u'CARY 27511') >>> result[2] (u'FARMINGTON WOODS', u'CARY 27511') >>> from grass.pygrass.vector.geometry import Point >>> pnt = Point(631213.349291, 224684.900084) >>> school = schools.find.geo(pnt, maxdist=300.) >>> school.attrs['NAMELONG'] u'ADAMS ELEMENTARY' >>> for school in schools.find.geos(pnt, maxdist=1000.): ... print school.attrs['NAMELONG'] ... CARY HIGH EAST CARY MIDDLE SITE ADAMS ELEMENTARY >>> schools.close() >>> zipcodes.close() """ def __init__(self, c_mapinfo, table=None, writable=False): """Find geometry feature around a point. """ self.c_mapinfo = c_mapinfo self.table = table self.writable = writable self.vtype = {'point': libvect.GV_POINT, # 1 'line': libvect.GV_LINE, # 2 'boundary': libvect.GV_BOUNDARY, # 3 'centroid': libvect.GV_CENTROID, # 4 'all': -1} # -1 # TODO: add the Node class and enable this method # def node(self, point, maxdist): # """Find the nearest node. Vect_find_node""" # i = libvect.Vect_find_node(self.c_mapinfo, point.x, point.y, point.z, # float(maxdist), int(not point.is2D)) # return geometry.Node(self.c_mapinfo.contents.plus.contents.Node[i]) @must_be_open def geo(self, point, maxdist, type='all', exclude=0): """Find the nearest line. Vect_find_line Valid type are all the keys in find.vtype dictionary """ feature_id = libvect.Vect_find_line(self.c_mapinfo, point.x, point.y, point.z if point.z else 0, self.vtype[type], float(maxdist), int(not point.is2D), exclude) if feature_id: return read_line(feature_id, self.c_mapinfo, self.table, self.writable) @must_be_open def geos(self, point, maxdist, type='all', exclude=[]): """Find the nearest line. Vect_find_line_list Valid type are all the keys in find.vtype dictionary """ excl = Ilist(exclude) found = Ilist() if libvect.Vect_find_line_list(self.c_mapinfo, point.x, point.y, point.z if point.z else 0, self.vtype[type], float(maxdist), int(not point.is2D), excl.c_ilist, found.c_ilist): return [read_line(f_id, self.c_mapinfo, self.table, self.writable) for f_id in found] else: return [] @must_be_open def area(self, point): """Find the nearest area. Vect_find_area""" area_id = libvect.Vect_find_area(self.c_mapinfo, point.x, point.y) if area_id: return Area(v_id=area_id, c_mapinfo=self.c_mapinfo, table=self.table, writable=self.writable) @must_be_open def island(self, point): """Find the nearest island. Vect_find_island""" isle_id = libvect.Vect_find_island(self.c_mapinfo, point.x, point.y) if isle_id: return Isle(v_id=isle_id, c_mapinfo=self.c_mapinfo, table=self.table, writable=self.writable) def is_open(self): """Check if the vector map is open or not""" import abstract return abstract.is_open(self.c_mapinfo)