MapComplete/scripts/csvToGeojson.ts

import {parse} from 'csv-parse/sync';
import {readFileSync} from "fs";

var lambert72toWGS84 = function(x, y){

    var newLongitude, newLatitude;

    var n = 0.77164219,
        F = 1.81329763,
        thetaFudge = 0.00014204,
        e = 0.08199189,
        a = 6378388,
        xDiff = 149910,
        yDiff = 5400150,
        theta0 = 0.07604294;

    var xReal = xDiff - x,
        yReal = yDiff - y;

    var rho = Math.sqrt(xReal * xReal + yReal * yReal),
        theta = Math.atan(xReal / -yReal);

    newLongitude = (theta0 + (theta + thetaFudge) / n) * 180 / Math.PI;
    newLatitude = 0;

    for (var i = 0; i < 5 ; ++i) {
        newLatitude = (2 * Math.atan(Math.pow(F * a / rho, 1 / n) * Math.pow((1 + e * Math.sin(newLatitude)) / (1 - e * Math.sin(newLatitude)), e / 2))) - Math.PI / 2;
    }
    newLatitude *= 180 / Math.PI;
    return [newLongitude, newLatitude];

}

function main(args: string[]): void {

    
    
    if (args.length == 0) {
   /*     args = ["/home/pietervdvn/Downloads/Scholen/aantallen.csv",
            "/home/pietervdvn/Downloads/Scholen/perschool.csv",
            "/home/pietervdvn/Downloads/Scholen/Vestigingsplaatsen-van-scholen-gewoon-secundair-onderwijs-cleaned.csv"]
    */
    console.log("Usage: csvToGeojson input.csv name-of-lat-field name-of-lon-field")
        return
    }
    
    let file =  args[0]
    if(file.startsWith("file://")){
        file = file.substr("file://".length)
    }
    const latField = args[1]
    const lonField = args[2]
    
    const csvOptions = {
        columns: true,
        skip_empty_lines: true,
        trim: true
    }
    
    const csv: Record<any, string>[] = parse(readFileSync(file), csvOptions)
    
   const features =  csv.map((csvElement, i) => {
        const lat = Number(csvElement[latField])
        const lon = Number(csvElement[lonField])
       if(isNaN(lat) || isNaN(lon)){
           throw `Not a valid lat or lon for entry ${i}: ${JSON.stringify(csvElement)}`
       }
       
       

       return {
            type: "Feature",
            properties: csvElement,
            geometry: {
                type: "Point",
                coordinates: lambert72toWGS84(lon, lat)
            }
        }
        
    })
    
    console.log(JSON.stringify({
        type: "FeatureCollection",
        features
    }))

}

main(process.argv.slice(2))