mongoDB Geospatial Query $geoWithin got error 'Loop is not closed' - mongodb

i am newbie for Geospatial Query of mongodb and i try search for point within polygon which have code like below :
db.properties.find({
location:{
$geoWithin : {
$geometry : {
type:"Polygon",
coordinates: [[
[104.9172382, 11.57934524],
[104.9146632, 11.5724502],
[104.92753788, 11.57976566]
]]
}
}
}
})
and my data table look like below :
i want to get result of all point is inside polygon.but i really have no clue
this error alway popup
|____/ Mongo Server error (MongoQueryException): Query failed with
error code 2 and error message 'Loop is not closed: [ [ 104.9172382,
11.57934524 ], [ 104.9146632, 11.5724502 ], [ 104.92753788, 11.57976566 ] ]' on server
thank for any idea !

i found answer that we need to start coordinate and close coordinates are the same value.
db.properties.find({
location:{
$geoWithin : {
$geometry : {
type:"Polygon",
coordinates:[
[
[ 104.9212999921292 , 11.575955591122819 ] , // start loop
[ 104.92129194550216 , 11.575198826419006 ] ,
[ 104.92298978380859 , 11.575238241297862 ] ,
[ 104.92291736416519 , 11.576023910057827 ] ,
[ 104.9212999921292 , 11.575955591122819 ] // close loop
]
]
}
}
}
})

Related

Geo-query using a circle as area to match at least one of the points of MultiPoint object in MongoDB

I have the following document in the entities collection at Mongo (a 2dsphere index for location.coords is in place):
> db.entities.find({},{location: 1}).pretty()
{
"_id" : {
"id" : "en3",
"type" : "t",
"servicePath" : "/"
},
"location" : {
"attrName" : "position",
"coords" : {
"type" : "MultiPoint",
"coordinates" : [
[
-3.691944,
40.418889
],
[
4.691944,
45.418889
]
]
}
}
}
As far as I have checked, $geoWithin only matches when the geometry includes all the points of the MultiPoint, e.g:
> db.entities.find({"location.coords": { $geoWithin: { $centerSphere: [ [ -3.691944, 40.418889 ], 0.002118976612776644 ] } } })
// Small circle centered at first point, but without covering the second point: it doesn't matchh
> db.entities.find({"location.coords": { $geoWithin: { $centerSphere: [ [ -3.691944, 40.418889 ], 2 ] } } })
// Big circle centered at first point covering also the second point: it matches
However, I would like to have a query to match if at least one point of the MultiPoint matches. I have read about the $geoIntersects operator. I have tried just replace $geoWithin by $geoIntersect in my query, but it doesn't work:
> db.entities.find({"location.coords": { $geoIntersects: { $centerSphere: [ [ -3.691944, 40.418889 ], 0.002118976612776644 ] } } })
error: {
"$err" : "Can't canonicalize query: BadValue bad geo query",
"code" : 17287
}
Reading the $geoIntersects operator, it seems that it can be only used with polygons or multi-polygons, but it doesn't mention circles. I wonder if I'm missing something, because this "asymmetry" between $geoWithin and $geoIntersects seems to be a bit weird...
Thus, is there any way of doing a geo-query using a circle as area to match at least one of the points of MultiPoint object?
I think I have found the answer at the end. It can be done with the $near operator, in the following way:
db.entities.find({"location.coords": { $near: { $geometry: { type: "Point", "coordinates": [ -3.691944, 40.418889 ] }, $maxDistance: 0.5 } }})

determine which predefined graphical region a user is in using mongodb

using mongo, I would like to compare a user's geo coordinates to a collection of documents each representing a defined geographical boundary. This is what i have thought to do, but cant get working. Other suggestions to get the same result are also welcome.
A document from the collection looks like this (those are manhattan coordinates, if you draw a line in sequence from one coordinate to the next, it wraps manhattan)
{
"__v" : 1,
"_id" : ObjectId("53220803a74a16da9c729202"),
"name" : "Manhattan",
"boundary" : {
"type" : "Polygon",
"coordinates" : [
[
[
-74.01237999999999,
40.69967
],
[
-73.97895,
40.71076
],
[
-73.97169,
40.73049
],
[
-73.92828,
40.79605
],
[
-73.95547999999999,
40.82635
],
[
-74.00901,
40.75431
],
[
-74.01961,
40.7059
]
]
]
}
}
i then use the following query to make my check
db.collection.find( { boundary :
{ $geoIntersects :
{ $geometry :
{ type : "Point" ,
coordinates : [ [user_long, user_lat] ]
} } } } ).exec(function(err, city){
console.log(err, "error");
res.send({agent_count : city});
});

MongoDB can't parse query (2dsphere): $geoWithin:

I have the following objects in my Collection that look like the following:
{
"_id" : ObjectId("527d33a8623f6efd1c997440"),
"location" : {
"geometry" : {
"type" : "Point",
"coordinates" : [
-78.4067,
37.26725
]
},
"type" : "Feature",
"properties" : {
"name" : "Something here"
}
},
"name" : "Name of Object"
}
I have the following index:
{
"location.geometry" : "2dsphere"
}
I can do the following:
db.myCollection.find({'location.geometry':{'$near':{'$geometry':{'type':"Point", 'coordinates': [-78.406700,37.267250]}, '$maxDistance' : 1000 }}})
However, I can Not do the following:
db.myCollection.find( { 'location.geometry': { '$geoWithin':
{ '$geometry' :
{ 'type' : "Polygon",
'coordinates' : [ [ -118.108006, 34.046072], [ -117.978230, 34.041521] , [ -117.987328,33.913645 ]] } }
} } )
As it returns with the error:
error: {
"$err" : "can't parse query (2dsphere): { $geoWithin: { $geometry: { type: \"Polygon\", coordinates: [ [ -118.108006, 34.046072 ], [ -117.97823, 34.041521 ], [ -117.987328, 33.913645 ] ] } } }",
"code" : 16535
}
Am I using geoWithin wrong? Can it not be used on this index?
The polygon that you are providing for $geowithin query is incorrect. A polygon needs to have the same start and end point as per GeoJSON definition.
The correct query is:
db.myCollection.find( { 'location.geometry':
{ '$geoWithin':
{ '$geometry' :
{ 'type' : "Polygon",
'coordinates' : [
[ -118.108006, 34.046072],
[ -117.978230, 34.041521],
[ -117.987328,33.913645 ],
[ -118.108006, 34.046072]
]
}
}
}
}
);
Notice the updated coordinates array.
Clearly, what is mentioned here in MongoDB docs about implicit connection of Polygons is NOT incorrect. It says that when you define the polygon using $polygon in MongoDB, only then is the connection implicit. It says nothing about being smart and making an implicit connection in the GeoJSON polygon provided to the query.
In fact, if for some GeoJSON variable you are saying that its type is polygon and you are not connecting its start with the end, then you have not created a correct GeoJSON polygon in the first place.
There is an error in the MongoDB documentation on $geoWithin queries. While the documentation states that:
The last point specified is always implicitly connected to the first.
You can specify as many points, and therefore sides, as you like.
This is incorrect. The polygon needs to be closed. There is an open ticket about this in MongoDB Jira:
https://jira.mongodb.org/browse/DOCS-2029
So your first and last points need to be equal - you cannot depend on MongoDB to implicitly draw the last line of the polygon.

MongoDB How to find which polygon contains a specified Point?

I insert many polygons into MongoDB(2.4.8), and hope find the polygon a specified Point sits in. It seems a common question. But after reading all docs from google, I didn't get the result. So create this question.
e.g.
db.addr_poly.insert(
{ loc :
{ type : "Polygon" ,
coordinates : [ [ [ 0 , 0 ] , [ 3 , 6 ] , [ 6 , 1 ] , [ 0 , 0 ] ] ]
} })
db.addr_poly.insert(
{ loc :
{ type : "Polygon" ,
coordinates : [ [ [ 0 , 0 ] , [ -3 , -6 ] , [ -6 , -1 ] , [ 0 , 0 ] ] ]
} })
Now how to find the polygon which contains Point(1,1)?
Anybody can help me? Thanks a lot!
Use the $geoIntersects operator. It queries for all shapes which intersect the GeoJSON object you pass. When you pass a point to it, it should return all shapes which include that point. Keep in mind that the $geoIntersects operator only works for 2dsphere indexes, not for 2d indexes.
As #philipp said, you should use the $geoIntesects operator. I was having the hardest time trying to figure out the query. I figured I would share what it looks and it might save someone the trouble later.
db.addr_poly.find({
loc:{
$geoIntersects: {
$geometry: {
type: "Point" ,
coordinates: [1, 1]
}
}
}
});

Sorting on GeoWithin MongoDB

So I made this query:
db.zips.find( { loc : { $geoWithin : { $box :[ [ -90 , 30 ] , [ -80 , 40 ] ] } } } )
And here is one (out of many) outputs:
{ "city" : "APISON", "loc" : [ -85.016404, 35.014926 ], "pop" : 1614, "state" : "TN", "_id" : "37302" }
My question is how would i be able to sort this by population and limit it to 10? When i try {$sort{pop:1}} i get errors it doesn't know pop, also when i add {$limit:10} at the end or my query it doesn't limit it to 10 entries but only shows me the last column.
Any help would be greatly appreciated!
db.zips.find({loc:{$geoWithin:{$box:[[-90,30],[-80,40]]}}}).sort({pop:1}).limit(10)