function updateLayers(data) {
  const scatterplot = new deck.ScatterplotLayer({
    /* unique id of this layer */
    id: 'checkins',
    /* data: an array of objects */
    data,
    /* data accessors */
    getPosition: d => d.coordinates,     // returns longitude, latitude, [altitude]
    getRadius: d => Math.sqrt(d.count),  // returns radius in meters
    getColor: d => [255, 0, 0]           // returns R, G, B, [A] in 0-255 range
  })

  // Add the layer to deckgl:
  deckgl.setProps({layers: [ scatterplot ]});
}

// Layers can be added, removed or updated at any time:
updateLayers([
  {coordinates: [-122.402, 37.79], count: 412, address: '2nd & Market St'},
  // ...
]);