tornados by almccon

index.html

<!DOCTYPE html>
<meta charset="utf-8">
<style>

path {
  fill: #ccc;
  stroke: #fff;
  stroke-width: .5px;
}

path:hover {
  fill: #ddd;
}

</style>
<body>
<script src="//d3js.org/d3.v4.min.js"></script>
<script src="//d3js.org/topojson.v1.min.js"></script>
<script src="https://d3js.org/d3-interpolate.v0.9.min.js"></script>
<script src="https://d3js.org/d3-color.v0.5.min.js"></script>
<script src="https://d3js.org/d3-scale-chromatic.v0.3.min.js"></script>


<script>

var width = 960,
    height = 500;

var projection = d3.geoAlbersUsa()

var path = d3.geoPath(projection);

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);

var url = "https://gist.githubusercontent.com/mbostock/4090846/raw/d534aba169207548a8a3d670c9c2cc719ff05c47/us.json"

var tornado_url = "https://gist.githubusercontent.com/almccon/fe3bc0328b0ed0b0e1fcdfc09b63b9af/raw/7eab26fee34977c42cb39bb951f2e19572153dff/tornado_1.geojson";

d3.json(url, function(error, topology) {
d3.json(tornado_url, function(error, tornados) {

  if (error) throw error;
  
  console.log("topojson", topology)
  var geojson = topojson.feature(topology, topology.objects.states);
  console.log("geojson", geojson)

  svg.append("g").selectAll("path")
      .data(geojson.features)
    .enter().append("path")
      .attr("d", path);
  
  console.log("tornados", tornados);
  
  var colorScale = d3.scaleSequential(d3.interpolateRdYlBu);
  
  var yearScale = d3.scaleLinear()
    .domain([1950,2018])
  	.range([0,1])

  
  svg.append("g").selectAll("path")
      .data(tornados.features)
    .enter()
    .filter(function(d) {
    	return (d.properties.mag > 1);
    })
    .append("path")
  		.attr("opacity",0.0001)
  		.transition()
  		.delay(function(d){
    		return 5000*yearScale(+d.properties.yr);
  		})
      .attr("d", path)
  		.style("stroke", function(d) {
    		return colorScale(yearScale(+d.properties.yr));
  		})
  		.transition().duration(1000)
  		.attr("opacity",1)
  		.transition()
  		.delay(function(d){
    		return 4000;
  		})
  		.filter(function(d){ return +d.properties.yr < 2000;})
  		.transition().duration(1000)
  		.attr("opacity",0.0001)
  		.style("display","none")
  
});
});

</script>