Circle processor

Circle processor

Converts circle definitions of shapes to regular polygons which approximate them.

Table 6. Circle Processor Options

resp = client.indices.create(
    index="circles",
    mappings={
        "properties": {
            "circle": {
                "type": "geo_shape"
            }
        }
    },
)
print(resp)
resp1 = client.ingest.put_pipeline(
    id="polygonize_circles",
    description="translate circle to polygon",
    processors=[
        {
            "circle": {
                "field": "circle",
                "error_distance": 28,
                "shape_type": "geo_shape"
            }
        }
    ],
)
print(resp1)

response = client.indices.create(
  index: 'circles',
  body: {
    mappings: {
      properties: {
        circle: {
          type: 'geo_shape'
        }
      }
    }
  }
)
puts response
response = client.ingest.put_pipeline(
  id: 'polygonize_circles',
  body: {
    description: 'translate circle to polygon',
    processors: [
      {
        circle: {
          field: 'circle',
          error_distance: 28,
          shape_type: 'geo_shape'
        }
      }
    ]
  }
)
puts response

const response = await client.indices.create({
  index: "circles",
  mappings: {
    properties: {
      circle: {
        type: "geo_shape",
      },
    },
  },
});
console.log(response);
const response1 = await client.ingest.putPipeline({
  id: "polygonize_circles",
  description: "translate circle to polygon",
  processors: [
    {
      circle: {
        field: "circle",
        error_distance: 28,
        shape_type: "geo_shape",
      },
    },
  ],
});
console.log(response1);

PUT circles
{
  "mappings": {
    "properties": {
      "circle": {
        "type": "geo_shape"
      }
    }
  }
}
PUT _ingest/pipeline/polygonize_circles
{
  "description": "translate circle to polygon",
  "processors": [
    {
      "circle": {
        "field": "circle",
        "error_distance": 28.0,
        "shape_type": "geo_shape"
      }
    }
  ]
}

Using the above pipeline, we can attempt to index a document into the circles index. The circle can be represented as either a WKT circle or a GeoJSON circle. The resulting polygon will be represented and indexed using the same format as the input circle. WKT will be translated to a WKT polygon, and GeoJSON circles will be translated to GeoJSON polygons.

Circles that contain a pole are not supported.

Example: Circle defined in Well Known Text

In this example a circle defined in WKT format is indexed

resp = client.index(
    index="circles",
    id="1",
    pipeline="polygonize_circles",
    document={
        "circle": "CIRCLE (30 10 40)"
    },
)
print(resp)
resp1 = client.get(
    index="circles",
    id="1",
)
print(resp1)

response = client.index(
  index: 'circles',
  id: 1,
  pipeline: 'polygonize_circles',
  body: {
    circle: 'CIRCLE (30 10 40)'
  }
)
puts response
response = client.get(
  index: 'circles',
  id: 1
)
puts response

const response = await client.index({
  index: "circles",
  id: 1,
  pipeline: "polygonize_circles",
  document: {
    circle: "CIRCLE (30 10 40)",
  },
});
console.log(response);
const response1 = await client.get({
  index: "circles",
  id: 1,
});
console.log(response1);

PUT circles/_doc/1?pipeline=polygonize_circles
{
  "circle": "CIRCLE (30 10 40)"
}
GET circles/_doc/1

The response from the above index request:

{
  "found": true,
  "_index": "circles",
  "_id": "1",
  "_version": 1,
  "_seq_no": 22,
  "_primary_term": 1,
  "_source": {
    "circle": "POLYGON ((30.000365257263184 10.0, 30.000111397193788 10.00034284530941, 29.999706043744222 10.000213571721195, 29.999706043744222 9.999786428278805, 30.000111397193788 9.99965715469059, 30.000365257263184 10.0))"
  }
}

Example: Circle defined in GeoJSON

In this example a circle defined in GeoJSON format is indexed

resp = client.index(
    index="circles",
    id="2",
    pipeline="polygonize_circles",
    document={
        "circle": {
            "type": "circle",
            "radius": "40m",
            "coordinates": [
                30,
                10
            ]
        }
    },
)
print(resp)
resp1 = client.get(
    index="circles",
    id="2",
)
print(resp1)

response = client.index(
  index: 'circles',
  id: 2,
  pipeline: 'polygonize_circles',
  body: {
    circle: {
      type: 'circle',
      radius: '40m',
      coordinates: [
        30,
        10
      ]
    }
  }
)
puts response
response = client.get(
  index: 'circles',
  id: 2
)
puts response

const response = await client.index({
  index: "circles",
  id: 2,
  pipeline: "polygonize_circles",
  document: {
    circle: {
      type: "circle",
      radius: "40m",
      coordinates: [30, 10],
    },
  },
});
console.log(response);
const response1 = await client.get({
  index: "circles",
  id: 2,
});
console.log(response1);

PUT circles/_doc/2?pipeline=polygonize_circles
{
  "circle": {
    "type": "circle",
    "radius": "40m",
    "coordinates": [30, 10]
  }
}
GET circles/_doc/2

The response from the above index request:

{
  "found": true,
  "_index": "circles",
  "_id": "2",
  "_version": 1,
  "_seq_no": 22,
  "_primary_term": 1,
  "_source": {
    "circle": {
      "coordinates": [
        [
          [30.000365257263184, 10.0],
          [30.000111397193788, 10.00034284530941],
          [29.999706043744222, 10.000213571721195],
          [29.999706043744222, 9.999786428278805],
          [30.000111397193788, 9.99965715469059],
          [30.000365257263184, 10.0]
        ]
      ],
      "type": "Polygon"
    }
  }
}

Notes on Accuracy

Accuracy of the polygon that represents the circle is defined as error_distance. The smaller this difference is, the closer to a perfect circle the polygon is.

Below is a table that aims to help capture how the radius of the circle affects the resulting number of sides of the polygon given different inputs.

The minimum number of sides is 4 and the maximum is 1000.

Table 7. Circle Processor Accuracy