distance_between_nearest_points_along_line.ipynb

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  {
   "cell_type": "markdown",
   "id": "6ae74352-eeca-4792-a7f3-3a068eccc87c",
   "metadata": {},
   "source": [
    "# Distance between nearest points along line"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [],
   "source": [
    "import shapely.ops\n",
    "import shapely.wkt as wkt"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "79a88b2b-783a-4b5a-8ea8-b7307ea5c7f5",
   "metadata": {},
   "source": [
    "## Sample data"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "id": "58a7b769",
   "metadata": {},
   "outputs": [],
   "source": [
    "line = wkt.loads(\"LINESTRING (2 0.5, 1 1, -1 0, 1 0)\")\n",
    "pnt1 = wkt.loads(\"POINT (1.8 1)\")\n",
    "pnt2 = wkt.loads(\"POINT (0.1 0.1)\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "id": "e7d48176",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "image/svg+xml": "<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\" width=\"100.0\" height=\"100.0\" viewBox=\"-1.12 -0.12 3.24 1.2400000000000002\" preserveAspectRatio=\"xMinYMin meet\"><g transform=\"matrix(1,0,0,-1,0,1.0)\"><g><circle cx=\"0.1\" cy=\"0.1\" r=\"0.09720000000000001\" stroke=\"#555555\" stroke-width=\"0.032400000000000005\" fill=\"#66cc99\" opacity=\"0.6\" /><circle cx=\"1.8\" cy=\"1.0\" r=\"0.09720000000000001\" stroke=\"#555555\" stroke-width=\"0.032400000000000005\" fill=\"#66cc99\" opacity=\"0.6\" /><polyline fill=\"none\" stroke=\"#66cc99\" stroke-width=\"0.06480000000000001\" points=\"2.0,0.5 1.0,1.0 -1.0,0.0 1.0,0.0\" opacity=\"0.8\" /></g></g></svg>",
      "text/plain": [
       "<shapely.geometry.collection.GeometryCollection at 0x7ff5385cbd00>"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "line.union(pnt1).union(pnt2)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "308e0576-8686-4559-87e6-f18344882f6b",
   "metadata": {},
   "source": [
    "## Caculate sub-LineString"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "id": "1775f696-51a8-4f6d-bb0a-30706c82809b",
   "metadata": {},
   "outputs": [],
   "source": [
    "dist1 = line.project(pnt1)\n",
    "dist2 = line.project(pnt2)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "id": "c54db20e",
   "metadata": {},
   "outputs": [],
   "source": [
    "line2 = shapely.ops.substring(line, dist1, dist2)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "id": "e7d48176",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "image/svg+xml": "<svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\" width=\"100.0\" height=\"100.0\" viewBox=\"-1.112 -0.11199999999999999 3.024 1.2240000000000002\" preserveAspectRatio=\"xMinYMin meet\"><g transform=\"matrix(1,0,0,-1,0,1.0)\"><g><circle cx=\"0.1\" cy=\"0.1\" r=\"0.09072\" stroke=\"#555555\" stroke-width=\"0.03024\" fill=\"#66cc99\" opacity=\"0.6\" /><circle cx=\"1.8\" cy=\"1.0\" r=\"0.09072\" stroke=\"#555555\" stroke-width=\"0.03024\" fill=\"#66cc99\" opacity=\"0.6\" /><polyline fill=\"none\" stroke=\"#66cc99\" stroke-width=\"0.06048\" points=\"1.6400000000000001,0.6799999999999999 1.0,1.0 -1.0,0.0 0.09999999999999964,0.0\" opacity=\"0.8\" /></g></g></svg>",
      "text/plain": [
       "<shapely.geometry.collection.GeometryCollection at 0x7ff4dd25b490>"
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "line2.union(pnt1).union(pnt2)"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "a2d301ad-e028-49c3-ba17-8de34fca4e5e",
   "metadata": {},
   "source": [
    "## Calculate length"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "id": "a754445a-ba4b-40ef-a2b3-24fdc5bc1969",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "4.051609730299722"
      ]
     },
     "execution_count": 12,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "line2.length"
   ]
  }
 ],
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