检查从GEOS C函数“ GEOSGeom_createLinearRing_r”返回的几何时遇到错误

Question

[尝试为我的地区和城市生成多边形字段以进行地理标记。想法是将坐标与Gmaps分开保存。然后使用它们生成区域多边形。对于印度NCR等地区，您有多个城市，例如德里，诺伊达。古尔冈等。这些城市构成了多边形的子集。

因此，您创建了一个多边形并与每个城市一起保存，然后制作一个多面体以在区域级别进行保存。

遇到此错误。请帮助

from Geography.models import Region,City
from django.contrib.gis.geos import Polygon,MultiPolygon

coordinates={
    'JAL':{
    "type": "FeatureCollection",

    "features": [
        { "type": "Feature", "properties": { "Name": "jalandhar", "Description": "" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 75.510571, 31.384717, 0.0 ], [ 75.515237, 31.270770, 0.0 ], [ 75.683574,31.264225, 0.0 ], [ 75.672656,31.390200, 0.0 ] ] ] } }
        ]
    }
    }
def add_polygons():
    r = Region.objects.last()
    city_coordinates = coordinates[r.name]['features']
    polygon=None
    for cx in city_coordinates:
        coo_list_ = cx['geometry']['coordinates'][0]
        coo_list =[[item[0],item[1]] for item in coo_list_]
        name = cx['properties']['Name']
        city=City.objects.filter(name__iexact=name).first()
        p = Polygon(coo_list)
        if city:
            city.poly=p
            city.save()
        if polygon:
            polygon=polygon.union(p)
        else: polygon=MultiPolygon(p)
    r.poly=Polygon(polygon.shell)
    r.save()


add_polygons()

这是我得到的错误。关于创建线性环函数的一些事情。我试图浏览图书馆本身，但无济于事。

GEOSExceptionTraceback (most recent call last)
<ipython-input-5-81f3fb947f4f> in <module>()
     36 }
     37 
---> 38 add_polygons()

<ipython-input-5-81f3fb947f4f> in add_polygons()
     11         name = cx['properties']['Name']
     12         city=City.objects.filter(name__iexact=name).first()
---> 13         p = Polygon(coo_list)
     14         if city:
     15             city.poly=p

/home/ubuntu/.virtualenvs/C24Aegis/local/lib/python2.7/site-packages/django/contrib/gis/geos/polygon.pyc in __init__(self, *args, **kwargs)
     46                 n_holes = len(init_holes)
     47 
---> 48         polygon = self._create_polygon(n_holes + 1, (ext_ring,) + init_holes)
     49         super(Polygon, self).__init__(polygon, **kwargs)
     50 

/home/ubuntu/.virtualenvs/C24Aegis/local/lib/python2.7/site-packages/django/contrib/gis/geos/polygon.pyc in _create_polygon(self, length, items)
     79                 rings.append(r)
     80             else:
---> 81                 rings.append(self._construct_ring(r))
     82 
     83         shell = self._clone(rings.pop(0))

/home/ubuntu/.virtualenvs/C24Aegis/local/lib/python2.7/site-packages/django/contrib/gis/geos/polygon.pyc in _construct_ring(self, param, msg)
    106             return param
    107         try:
--> 108             ring = LinearRing(param)
    109             return ring
    110         except TypeError:

/home/ubuntu/.virtualenvs/C24Aegis/local/lib/python2.7/site-packages/django/contrib/gis/geos/linestring.pyc in __init__(self, *args, **kwargs)
     74         # Calling the base geometry initialization with the returned pointer
     75         #  from the function.
---> 76         super(LineString, self).__init__(self._init_func(cs.ptr), srid=srid)
     77 
     78     def __iter__(self):

/home/ubuntu/.virtualenvs/C24Aegis/local/lib/python2.7/site-packages/django/contrib/gis/geos/prototypes/threadsafe.pyc in __call__(self, *args)
     54             # Call the threaded GEOS routine with pointer of the context handle
     55             # as the first argument.
---> 56             return self.cfunc(self.thread_context.handle.ptr, *args)
     57         else:
     58             return self.cfunc(*args)

/home/ubuntu/.virtualenvs/C24Aegis/local/lib/python2.7/site-packages/django/contrib/gis/geos/prototypes/errcheck.pyc in check_geom(result, func, cargs)
     31     "Error checking on routines that return Geometries."
     32     if not result:
---> 33         raise GEOSException('Error encountered checking Geometry returned from GEOS C function "%s".' % func.__name__)
     34     return result
     35 

GEOSException: Error encountered checking Geometry returned from GEOS C function "GEOSGeom_createLinearRing_r".

Answer 1

通过本白皮书https://tools.ietf.org/html/rfc7946#section-3.1：

由于第一个和最后一个坐标必须相同，所以问题已解决。

所以坐标字典应该像

coordinates={
'JAL':{
"type": "FeatureCollection",

"features": [
    { "type": "Feature", "properties": { "Name": "jalandhar", "Description": "" }, "geometry": { "type": "Polygon", "coordinates": [ [ [ 75.510571, 31.384717, 0.0 ], [ 75.515237, 31.270770, 0.0 ], [ 75.683574,31.264225, 0.0 ], [ 75.672656,31.390200, 0.0 ],[ 75.510571, 31.384717, 0.0 ] ] ] } }
    ]
}
}