enjalot/.block

## .block
license: gpl-3.0

## README.md

      
    Raw
  

              README.md
            
          
    Working with spatial data

Example #16

Using turf.js to measure features
forked from mbostock's block: U.S. Counties TopoJSON
forked from enjalot's block: WWSD #12: d3 + TopoJSON
forked from enjalot's block: WWSD #13: d3 + Canvas

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

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

path:hover {
  fill: red;
}

</style>
<body>
  <canvas></canvas>
<script src="//d3js.org/d3.v3.min.js"></script>
<script src="//d3js.org/topojson.v1.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Turf.js/2.0.2/turf.min.js"></script>
<script>

var width = 960,
    height = 500;

var canvas = d3.select("canvas").node()
canvas.width = width;
canvas.height = height;
var ctx = canvas.getContext('2d')

var projection = d3.geo.mercator()
.center([-122.2615006,37.8469266])
.scale(2000)

var path = d3.geo.path()
  .projection(projection)
  .context(ctx)


var url = "http://enjalot.github.io/wwsd/data/USA/california-streams.topojson"
d3.json(url, function(error, topology) {
  if (error) throw error;

  console.log("topojson", topology)
  var geojson = topojson.feature(topology, topology.objects['us-streams-unmerged-18']);
  console.log("geojson", geojson)

  var maxLength = d3.max(geojson.features, function(d) {
    var length = turf.lineDistance(d, 'miles');
    d.properties.length = length;
    return length;
  })

  var color = d3.scale.threshold()
  .domain([0, 2, 20, maxLength])
  .range(["#853c3c", "#85763c", "#3c8544", "#0068b7"])

  ctx.strokeStyle = "#111";
  ctx.fillStyle = "#99ffe8"
  geojson.features.forEach(function(feature) {
    ctx.strokeStyle = color(feature.properties.length)
    ctx.beginPath()
    path(feature)
    ctx.stroke();
  })
});

</script>

## thumbnail.png

      
    Raw
  

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

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

	path:hover {
	fill: red;
	}

	</style>
	<body>
	<canvas></canvas>
	<script src="//d3js.org/d3.v3.min.js"></script>
	<script src="//d3js.org/topojson.v1.min.js"></script>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/Turf.js/2.0.2/turf.min.js"></script>
	<script>

	var width = 960,
	height = 500;

	var canvas = d3.select("canvas").node()
	canvas.width = width;
	canvas.height = height;
	var ctx = canvas.getContext('2d')

	var projection = d3.geo.mercator()
	.center([-122.2615006,37.8469266])
	.scale(2000)

	var path = d3.geo.path()
	.projection(projection)
	.context(ctx)


	var url = "http://enjalot.github.io/wwsd/data/USA/california-streams.topojson"
	d3.json(url, function(error, topology) {
	if (error) throw error;

	console.log("topojson", topology)
	var geojson = topojson.feature(topology, topology.objects['us-streams-unmerged-18']);
	console.log("geojson", geojson)

	var maxLength = d3.max(geojson.features, function(d) {
	var length = turf.lineDistance(d, 'miles');
	d.properties.length = length;
	return length;
	})

	var color = d3.scale.threshold()
	.domain([0, 2, 20, maxLength])
	.range(["#853c3c", "#85763c", "#3c8544", "#0068b7"])

	ctx.strokeStyle = "#111";
	ctx.fillStyle = "#99ffe8"
	geojson.features.forEach(function(feature) {
	ctx.strokeStyle = color(feature.properties.length)
	ctx.beginPath()
	path(feature)
	ctx.stroke();
	})
	});

	</script>