Circle radius propblem v8.5.3

[Dat_Le_Tien]

I'm trying to insert a location that is using a circle processor to generate the circle points. Location [30, 10] in the document is generated with the circle points properly.
docs: Circle processor | Elasticsearch Guide [8.5] | Elastic

PUT _ingest/pipeline/polygonize_circles
{
  "description": "translate circle to polygon",
  "processors": [
    {
      "circle": {
        "field": "circle",
        "error_distance": 1,
        "shape_type": "geo_shape"
      }
    }
  ]
}


PUT circles
{
  "mappings": {
    "properties": {
      "circle": {
        "type": "geo_shape"
      }
    }
  }
}
 

PUT circles/_doc/2?pipeline=polygonize_circles
{
  "circle": {
    "type": "circle",
    "radius": "40m",
    "coordinates": [35.539917, -78.472000]
  }
}

GET circles/_doc/2

But if I use another location. The generated coordinate looks like an oval with the wrong radius.

my location [35.54171753710938, -78.472]

created coordinates:
"circle": {
            "coordinates": [
              [
                [
                  35.54171753710938,
                  -78.472
                ],
                [
                  35.54112406581135,
                  -78.47173430472324
                ],
                [
                  35.540630197847186,
                  -78.47167003953963
                ],
                [
                  35.540375564960186,
                  -78.47165140797998
                ],
                [
                  35.54021828908823,
                  -78.47164529506406
                ],
                [
                  35.54010640465818,
                  -78.47164274491611
                ],
                [
                  35.54001650261309,
                  -78.47164162397662
                ],
                [
                  35.53993651647515,
                  -78.47164003979641
                ],
                [
                  35.539858062238046,
                  -78.47164049555624
                ],
                [
                  35.53977439153409,
                  -78.47164207973975
                ],
                [
                  35.5396750942597,
                  -78.47164321572573
                ],
                [
                  35.5395458932956,
                  -78.47164846905713
                ],
                [
                  35.539348254773515,
                  -78.47165779735127
                ],
                [
                  35.53899878746994,
                  -78.47169061817682
                ],
                [
                  35.53833938849573,
                  -78.47182842440924
                ],
                [
                  35.53833938849573,
                  -78.47217157559075
                ],
                [
                  35.53899878746994,
                  -78.47230938182317
                ],
                [
                  35.539348254773515,
                  -78.47234220264872
                ],
                [
                  35.5395458932956,
                  -78.47235153094286
                ],
                [
                  35.5396750942597,
                  -78.47235678427425
                ],
                [
                  35.53977439153409,
                  -78.47235792026024
                ],
                [
                  35.539858062238046,
                  -78.47235950444374
                ],
                [
                  35.53993651647515,
                  -78.47235996020358
                ],
                [
                  35.54001650261309,
                  -78.47235837602337
                ],
                [
                  35.54010640465818,
                  -78.47235725508388
                ],
                [
                  35.54021828908823,
                  -78.47235470493592
                ],
                [
                  35.540375564960186,
                  -78.47234859202001
                ],
                [
                  35.540630197847186,
                  -78.47232996046036
                ],
                [
                  35.54112406581135,
                  -78.47226569527675
                ],
                [
                  35.54171753710938,
                  -78.472
                ]
              ]
            ],
            "type": "Polygon"
          }

Is it an issue or It's working as expected? Because the coordinates are not a circle so it's impacting the search result.

[Ignacio_Vera]

This is working as expected, the circle processor "polygonize" the circle as the index does not support indexing circles natively.

[Dat_Le_Tien]

@Ignacio_Vera

Thanks for your reply. Is there any way to transform a point along with the radius to a circle similar CircleShape in ESS 6.8? We are doing the upgrade from 6.8 to 8.5.3 and got this issue by using the Circle Processor.
When I map the generated coordinate in Gooogle Maps. It looks like this.

[Ignacio_Vera]

I tried your first example and indeed the generated polygon looks in kibana maps like :

But this is a problem of the precision you are using. If I change the precision to 0.001:

PUT _ingest/pipeline/polygonize_circles
{
  "description": "translate circle to polygon",
  "processors": [
    {
      "circle": {
        "field": "circle",
        "error_distance": 0.01,
        "shape_type": "geo_shape"
      }
    }
  ]
}

Then it looks much better:

Could you explain how are you generating the second example? I tried to see if I can reproduce it but I could not. I tried the following:

PUT _ingest/pipeline/polygonize_circles
{
  "description": "translate circle to polygon",
  "processors": [
    {
      "circle": {
        "field": "circle",
        "error_distance": 100,
        "shape_type": "geo_shape"
      }
    }
  ]
}

PUT circles/_doc/2?pipeline=polygonize_circles
{
  "circle": {
    "type": "circle",
    "radius": "2000m",
    "coordinates": [-122.25, 37.47]
  }
}

And it looks like:

[Dat_Le_Tien]

Sorry. I missed it. The input coordinate should be lon, lat instead of lat, lon. It's working now.