Hello I am working with a large geojson dataset, and I am trying to see if I can merge the coordinate values of each entry based on entries that share the same "User_ID".
My dataset look like this:
{
"geometry":{
"type":"Point",
"coordinates":[
-3.231658,
51.687026
]
},
"type":"Feature",
"properties":{
"User_ID":1002848324
}
},
{
"geometry":{
"type":"Point",
"coordinates":[
-3.231659,
51.687016
]
},
"type":"Feature",
"properties":{
"User_ID":1002848324
}
}
I have tried to merge the entries using the method shown in mwarren's answer, url: "https://stackoverflow.com/questions/29244116/merge-geojson-based-on-unique-id".
Yet this comes with the small problem that "attr" is seen as an "Unexpected Identifier" when I try to run a test.
My test of the code so far is as follows:
features.map(function(feature){
var matchedArray = features2.filter(function(feature2){
return feature2.User_ID === feature.User_ID;
});
if(matchedArray && matchedArray[0]){
for(var attr in matchedArray[0].properties){
feature.properties[attr] = matchedArray[0].properties[attr];
}
}
});
The desired result should look something like this:
{
"geometry":{
"type":"Point",
"coordinates":[
-3.231658,
51.687026
], [
-3.231659,
51.687016
]
},
"type":"Feature",
"properties":{
"User_ID":1002848324
}
Any help will be greatly appreciated.
From the above comment ...
"The OP needs to group/collect the data not only by same
User_IDvalues but by both sametypeAND sameUser_IDvalues"
... and maybe even by same geometry.type. A just User_ID based grouping/collecting is not explicit enough because items of same User_ID values might feature different type values or might even differ in their geometry.type values.
A reduce based task which uses a collector object which features an object as lookup and an result array for the aggregated final data does solve the OP's task within one iteration step ...
function collectSameGeoCategoryItems(collector, item) {
const { lookup, result } = collector;
const { properties: { User_ID }, type } = item;
const groupKey = `${ type }_${ User_ID }`;
let groupItem = lookup[groupKey];
if (groupItem) {
// push coordinates copy into existing array of coordinate arrays.
groupItem.geometry.coordinates.push([...item.geometry.coordinates]);
} else {
// create full copy of geo item in order
// to not mutate the original reference.
groupItem = lookup[groupKey] = {
geometry: {
type: item.geometry.type,
coordinates: [ [...item.geometry.coordinates] ],
},
type,
properties: { User_ID },
};
result.push(groupItem);
}
return collector;
}
const sampleData = [{
geometry: {
type: "Point",
coordinates: [
-3.231658,
51.687026,
],
},
type: "Feature",
properties: {
User_ID: 1002848324,
},
}, {
geometry: {
type: "Point",
coordinates: [
-3.231659,
51.687016,
],
},
type: "Feature",
properties: {
User_ID: 1002848324,
},
}, {
geometry: {
type: "Point",
coordinates: [
-3.231658,
51.687026,
],
},
type: "Foo",
properties: {
User_ID: 1002848324,
},
}, {
geometry: {
type: "Point",
coordinates: [
-3.231659,
51.687016,
],
},
type: "Bar",
properties: {
User_ID: 1002848324,
},
}, {
geometry: {
type: "Point",
coordinates: [
-3.231658,
51.687026,
],
},
type: "Foo",
properties: {
User_ID: 1000000000,
},
}, {
geometry: {
type: "Point",
coordinates: [
-3.231659,
51.687016,
],
},
type: "Bar",
properties: {
User_ID: 1002848324,
},
}];
console.log(
'aggregated `result` ...',
sampleData.reduce(collectSameGeoCategoryItems, { lookup: {}, result: [] }).result
);
console.log('unmutated sample data ... ', { sampleData });
console.log(
'aggregated `lookup`, not needed, just for demonstration purpose ...',
sampleData.reduce(collectSameGeoCategoryItems, { lookup: {}, result: [] }).lookup
);.as-console-wrapper { min-height: 100%!important; top: 0; }You have spelled var to "war" which needs to be 'var'. and if this is not a mistake please specify what is 'features2' array.