MongoDB find polygon coordinates using single point and radius - mongodb

Question

I have a collection with many polygon coordinates, which represent the different areas.
What my objective is I will send a lat, long and radius in a mongodb query which should return the polygon coordinates that falls within circle area.
Polygon coordinates:
{
"_id" : "300",
"name" : "MeKesler",
"centroid" : [
0,
0
],
"type" : "cnbd_id",
"coords" : [
[
39.8620784017,
-86.14614844330004
],
[
39.8625395793,
-86.15442037579999
],
[
39.8593030353,
-86.156373024
],
[
39.8586935926,
-86.15669488909998
],
[
39.8534225112,
-86.15854024890001
],
[
39.850391456,
-86.1589050293
],
[
39.8511657057,
-86.1479830742
],
[
39.8511986523,
-86.14598751070002
],
[
39.856881704,
-86.14605188370001
],
[
39.8575241063,
-86.14605188370001
],
[
39.8620784017,
-86.14614844330004
]
]
}
My query:
db.collection.find({
"coords" : {
"$within" : {
"$center" : [
[ 39.863110, -86.168456],
2/69.1
]
}
}
})
Can anyone help on this?

Answer 1

I believe the problem is that your document is not valid geojson. The valid syntax for your polygon would be
{
"_id": "300",
"name": "MeKesler",
"centroid": {
type: "Point",
coordinates: [0, 0]
},
"type": "cnbd_id",
"geometry": {
"type": "Polygon",
"coordinates": [
[
[39.8620784017, -86.14614844330004],
[39.8625395793, -86.15442037579999],
[39.8593030353, -86.156373024],
[39.8586935926, -86.15669488909998],
[39.8534225112, -86.15854024890001],
[39.850391456, -86.1589050293],
[39.8511657057, -86.1479830742],
[39.8511986523, -86.14598751070002],
[39.856881704, -86.14605188370001],
[39.8575241063, -86.14605188370001],
[39.8620784017, -86.14614844330004]
]
]
}
}
Also, you should consider creating a 2dsphere index on the geometry field.
Lastly, the geo query should use the $geoWithin operator, and run against the polygon, not against its coordinates.
db.collection.find({
"geometry" : {
"$geoWithin" : {
"$center" : [
[ 39.863110, -86.168456],
2/69.1
]
}
}
})