Mapping LA

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <meta name='viewport' content='initial-scale=1,maximum-scale=1,user-scalable=no' />
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <script src='https://api.mapbox.com/mapbox-gl-js/v0.31.0/mapbox-gl.js'></script>
  <link href='https://api.mapbox.com/mapbox-gl-js/v0.31.0/mapbox-gl.css' rel='stylesheet' />

<body>
  <div id="map"></div>
  <script>
    function buildUrl(url, queryParams) {
      url += '?';
      queryParams.forEach(function(param){
        url += `${param}&`
      })
      return url.slice(0, -1);
    }
  </script>

const container = map.getCanvasContainer();
    const canvas = d3.select(container).append('canvas').node();
    const boundingBox = document.body.getBoundingClientRect();
    canvas.width = boundingBox.width;
    canvas.height = boundingBox.height;
    const context = canvas.getContext('2d');
      
    const url06To16 = 'https://data.lacounty.gov/resource/hvzm-fn38.json';

d3.queue()
        // .defer(d3.json, 'https://data.lacounty.gov/resource/mdji-9cym.json')
        .defer(d3.json, buildUrl(url06To16, [
          '$where=units > 22', '$limit=20000', 'yearbuilt=1989'
        ]))
      .await(initialRender)

function initialRender(error, propertyData) {
      if (error) return console.warn(error);

console.log(
        propertyData.length,
        propertyData[0], 
        getLatLong(propertyData[0]), 
        project(propertyData[0])
      )
      
      // Initial render
      render(propertyData);

// re-render our visualization whenever the view changes
      map.on('viewreset', function() {
        context.clearRect(0, 0, boundingBox.width, boundingBox.height);
        render(propertyData);
      })
      map.on('move', function() {
        context.clearRect(0, 0, boundingBox.width, boundingBox.height);
        render(propertyData);
      })
    }

function render(data) {
      const propertyValues = data.reduce(function(_propertyValues, property){
        if (property.roll_totlandimp) {
          _propertyValues.push(+property.roll_totlandimp);
        }
        return _propertyValues;
      }, []);

const propertyValueColor = d3.scaleLog()
        .range(['hsl(62,100%,90%)', 'hsl(228,30%,20%)'])
        .domain([d3.quantile(propertyValues, .01), d3.quantile(propertyValues, .99)])
        .interpolate(d3.interpolateHcl);

context.clearRect(0, 0, boundingBox.width, boundingBox.height);

data.forEach(function(property, idx) {
        const point = project(property);
        if (point) {
          context.fillStyle = propertyValueColor(+property.roll_totlandimp);
          context.beginPath();
          context.arc(point.x, point.y, 4, 0, Math.PI * 2);
          context.fill();
          // context.stroke();
        }
      })
    }
  </script>
</body>

https://d3js.org/d3.v4.min.js

https://api.mapbox.com/mapbox-gl-js/v0.31.0/mapbox-gl.js