删除具有一个或多个共同边部分的多边形

Question

我正在尝试解决将多边形与其他多边形进行比较的特殊情况。我有 5 个多边形分布如下图所示。黑色多边形是面积最大的那个。

可能还有其他类似的情况，主要规则是在所有具有一个或多个边部分的所有多边形中删除最小的多边形。

本案例的数据在 GeoJson 文件中，如下所示：

{"type":"FeatureCollection","features":[
    {"type":"Feature","properties":{"id":1},"geometry":{"type":"Polygon","coordinates":[[[3.4545135498046875,45.533288879467456],[3.4960556030273433,45.533288879467456],[3.4960556030273433,45.57055337226086],[3.4545135498046875,45.57055337226086],[3.4545135498046875,45.533288879467456]]]}},
    {"type":"Feature","properties":{"id":2},"geometry":{"type":"Polygon","coordinates":[[[3.4545135498046875,45.52917023833511],[3.4960556030273433,45.52917023833511],[3.4960556030273433,45.53891018749409],[3.4545135498046875,45.53891018749409],[3.4545135498046875,45.52917023833511]]]}},
    {"type":"Feature","properties":{"id":3},"geometry":{"type":"Polygon","coordinates":[[[3.4845542907714844,45.5298015824607],[3.5159683227539062,45.5298015824607],[3.5159683227539062,45.543388795387294],[3.4845542907714844,45.543388795387294],[3.4845542907714844,45.5298015824607]]]}},
    {"type":"Feature","properties":{"id":4},"geometry":{"type":"Polygon","coordinates":[[[3.465328216552734,45.542667432984864],[3.4735679626464844,45.542667432984864],[3.4735679626464844,45.5478369923404],[3.465328216552734,45.5478369923404],[3.465328216552734,45.542667432984864]]]}},
    {"type":"Feature","properties":{"id":5},"geometry":{"type":"Polygon","coordinates":[[[3.4545138850808144,45.56799974017372],[3.4588050842285156,45.56799974017372],[3.4588050842285156,45.57055290285386],[3.4545138850808144,45.57055290285386],[3.4545138850808144,45.56799974017372]]]}}]}

是否有删除仅两个 blue 多边形（id 2 和 5）的解决方案？在 python.

通过将多边形转换为 LineString，可以查看 Linestring 是否是另一个 Linestring 的一部分？但我不知道该怎么做。或者查看黑色和蓝色多边形的 LineString 是否有两个以上的共同点？但是我们不能将一个LineString转换成两个以上的点。

Answer 1

使用 shared_paths 以下方法可能对您有用，它正确地指出了多边形 1、2 和 5 之间的路径重叠：

import json
import shapely as sh
import shapely.ops as ops
import shapely.geometry as geo

with open('./test.json') as f:
  features = json.load(f)['features']

for f1 in features:
  for f2 in features:
    id1 = f1['properties']['id']
    id2 = f2['properties']['id']
    if int(id1) > int(id2):
      s1 = geo.shape(f1['geometry'])
      s2 = geo.shape(f2['geometry'])
      coll = ops.shared_paths(s1.boundary, s2.boundary)
      if not coll.is_empty:
        print(f"{id1} and {id2} have shared path")
        # update your feature collection etc

我不得不将要素几何中的精度降低到小数点后 5 位，因为最初它只检测多边形 1 和 2 之间的重叠。多边形 1 和 5 之间的共享角在您的输入中略微超出特征集合：

{
  "type": "FeatureCollection",
  "features": [{
      "type": "Feature",
      "properties": {
        "id": 1
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [3.45451, 45.53328],
            [3.49605, 45.53328],
            [3.49605, 45.57055],
            [3.45451, 45.57055],
            [3.45451, 45.53328]
          ]
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "id": 2
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [3.45451, 45.52917],
            [3.49605, 45.52917],
            [3.49605, 45.53891],
            [3.45451, 45.53891],
            [3.45451, 45.52917]
          ]
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "id": 3
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [3.48455, 45.52980],
            [3.51596, 45.52980],
            [3.51596, 45.54338],
            [3.48455, 45.54338],
            [3.48455, 45.52980]
          ]
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "id": 4
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [3.465328, 45.54266],
            [3.473567, 45.54266],
            [3.473567, 45.54783],
            [3.465328, 45.54783],
            [3.465328, 45.54266]
          ]
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "id": 5
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [3.454513, 45.56799],
            [3.458805, 45.56799],
            [3.458805, 45.57055],
            [3.454513, 45.57055],
            [3.454513, 45.56799]
          ]
        ]
      }
    }
  ]
}

删除具有一个或多个共同边部分的多边形

Delete polygons that have one or more side parts in common

python

geojson

shapely