mbostock/.block

## .block
license: gpl-3.0

## README.md

      
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              README.md
            
          
    This example demonstrates how to create a custom Cartesian projection by implementing a geometry transform on top of two linear scales; the geometry transform is then used in lieu of a geographic projection, which are intended for displaying spherical geometry.

  
## geo.json

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

.lot {
  fill: lightgray;
  stroke: black;
}

</style>
<svg width="960" height="500"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>

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

var x = d3.scaleLinear()
    .range([0, width]);

var y = d3.scaleLinear()
    .range([0, height]);

var projection = d3.geoTransform({
  point: function(px, py) {
    this.stream.point(x(px), y(py));
  }
});

var path = d3.geoPath()
    .projection(projection);

d3.json("geo.json", function(error, geo) {
  if (error) throw error;

  x.domain(d3.extent(geo.features, function(d) { return d.properties.Easting; }));
  y.domain(d3.extent(geo.features, function(d) { return d.properties.Northing; }));

  svg.append("path")
      .datum(geo)
      .attr("class", "lot")
      .attr("d", path);
});

</script>

## thumbnail.png

      
    Raw
  

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

	.lot {
	fill: lightgray;
	stroke: black;
	}

	</style>
	<svg width="960" height="500"></svg>
	<script src="https://d3js.org/d3.v4.min.js"></script>
	<script>

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

	var x = d3.scaleLinear()
	.range([0, width]);

	var y = d3.scaleLinear()
	.range([0, height]);

	var projection = d3.geoTransform({
	point: function(px, py) {
	this.stream.point(x(px), y(py));
	}
	});

	var path = d3.geoPath()
	.projection(projection);

	d3.json("geo.json", function(error, geo) {
	if (error) throw error;

	x.domain(d3.extent(geo.features, function(d) { return d.properties.Easting; }));
	y.domain(d3.extent(geo.features, function(d) { return d.properties.Northing; }));

	svg.append("path")
	.datum(geo)
	.attr("class", "lot")
	.attr("d", path);
	});

	</script>