How to convert a point to polygon? - polygon

Question

I have a big data in GeoJSON with Point type like this:
{
"type": "FeatureCollection",
"features": [
{
"type": "Feature",
"properties": {},
"geometry": {
"type": "Point",
"coordinates": [
2.8125,
47.040182144806664
]
}
},
{
"type": "Feature",
"properties": {},
"geometry": {
"type": "Point",
"coordinates": [
14.765625,
48.69096039092549
]
}
}
]
}
As far as I know, in order to create polygon on a map, my GeoJSON should have Polygon as a Type instead of Points. How can I do it? Does anybody have idea? Should I convert them into polygon? How? I really need your help guys... (I am using Mapbox-Gl-Js by the way)
Thanks!

Answer 1

was having same issue searched for ages then found this lib Terraformer, (http://terraformer.io/core/#terraformercircle), one of the methods allows you to specify a long and lat point, and convert that into a circle around that point.
See my implementation below or you can also go through the docs
http://terraformer.io/core/#terraformercircle
//get the Terraformer lib
var Terraformer = require("terraformer");
const getPolygonFromPoints = async => {
//get the geoJSON
const getPointBasedGeoJSON = await require({localresource}); //or use a fetch if it is an external resource.
//loop over all the featues using ES6 map, to generate a new array of polygon based coordinates
const polygonBasedGeoJSON = getPointBasedGeoJSON.features.map(d => ({
type: "Feature",
...new Terraformer.Circle(
[d.geometry.coordinates[0], d.geometry.coordinates[1]],
500, //The radius of the circle in meters.
5 //How many steps will be used to create the polygon that represents the circle. i.e number of poins in the polyon array
),
/*
Terraformer.Circle will retrun an object similar to this, which we need to spread into our parent object, hence the ES6 spread
"geometry": {
"type": "Point",
"coordinates": [array of polygon coordinates based on the point you referenced]
},
*/
point: [d.geometry.coordinates[0], d.geometry.coordinates[1]], //so that you can still reference a point
properties: {
//specify any properties
}
}));
if (polygonBasedGeoJSON.length > 0){
return polygonBasedGeoJSON
}
return []
}
//Points to Polygon collection ready for use
console.log(getPolygonFromPoints())

Answer 2

It's simple: I had a data regarding terrorism in csv with latitude, longitude. When i converted it to geojson I had a structure like this:
{
"type": "FeatureCollection",
"features": [
{
"type": "Feature",
"properties": {},
"geometry": {
"type": "Point",
"coordinates": [
2.8125,
47.040182144806664
]
}
}
The question was: how I can create a map like this using this data: terrorism_map
I know that my geojson is useless in this case, but i need a way of creating map using this data. Sorry to confuse...