elktamer/index.html

## readme.md

      
    Raw
  

              readme.md
            
          
## index.html
<!DOCTYPE html>
<meta charset="utf-8">
<title>Canada Budget 2016</title>
<style>

.node rect {
  cursor: move;
  fill-opacity: .9;
  shape-rendering: crispEdges;
}

.node text {
  pointer-events: none;
  text-shadow: 0 1px 0 #fff;
}

.link {
  fill: none;
  stroke: #000;
  stroke-opacity: .2;
}

.link:hover {
  stroke-opacity: .5;
}

</style>
<body>

<p id="chart">

<script src="http://d3js.org/d3.v3.min.js"></script>
<script src="sankey.js"></script>
<script>

var units = "billions";

var margin = {top: 10, right: 10, bottom: 10, left: 10},
    width = 1000 - margin.left - margin.right,
    height = 800 - margin.top - margin.bottom;

var formatNumber = d3.format(",.0f"),    // zero decimal places
    format = function(d) { return formatNumber(d) + " " + units; },
    color = d3.scale.category20();

// append the svg canvas to the page
var svg = d3.select("#chart").append("svg")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform",
          "translate(" + margin.left + "," + margin.top + ")");

// Set the sankey diagram properties
var sankey = d3.sankey()
    .nodeWidth(9)
    .nodePadding(10)
    .size([width, height]);

var path = sankey.link();

// load the data (using the timelyportfolio csv method)
d3.csv("sankey.csv", function(error, data) {

  //set up graph in same style as original example but empty
  graph = {"nodes" : [], "links" : []};

    data.forEach(function (d) {
      graph.nodes.push({ "name": d.source });
      graph.nodes.push({ "name": d.target });
      graph.links.push({ "source": d.source,
                         "target": d.target,
                         "value": +d.value });
     });

     // return only the distinct / unique nodes
     graph.nodes = d3.keys(d3.nest()
       .key(function (d) { return d.name; })
       .map(graph.nodes));

     // loop through each link replacing the text with its index from node
     graph.links.forEach(function (d, i) {
       graph.links[i].source = graph.nodes.indexOf(graph.links[i].source);
       graph.links[i].target = graph.nodes.indexOf(graph.links[i].target);
     });

     //now loop through each nodes to make nodes an array of objects
     // rather than an array of strings
     graph.nodes.forEach(function (d, i) {
       graph.nodes[i] = { "name": d };
     });

  sankey
    .nodes(graph.nodes)
    .links(graph.links)
    .layout(32);

// add in the links
  var link = svg.append("g").selectAll(".link")
      .data(graph.links)
    .enter().append("path")
      .attr("class", "link")
      .attr("d", path)
      .style("stroke-width", function(d) { return Math.max(1, d.dy); })
      .sort(function(a, b) { return b.dy - a.dy; });

// add the link titles
  link.append("title")
        .text(function(d) {
    		return d.source.name + " → " +
                d.target.name + "\n" + format(d.value); });

// add in the nodes
  var node = svg.append("g").selectAll(".node")
      .data(graph.nodes)
    .enter().append("g")
      .attr("class", "node")
      .attr("transform", function(d) {
		  return "translate(" + d.x + "," + d.y + ")"; })
    .call(d3.behavior.drag()
      .origin(function(d) { return d; })
      .on("dragstart", function() {
		  this.parentNode.appendChild(this); })
      .on("drag", dragmove));

// add the rectangles for the nodes
  node.append("rect")
      .attr("height", function(d) { return d.dy; })
      .attr("width", sankey.nodeWidth())
      .style("fill", function(d) {
		  return d.color = color(d.name.replace(/ .*/, "")); })
      .style("stroke", function(d) {
		  return d3.rgb(d.color).darker(2); })
    .append("title")
      .text(function(d) {
		  return d.name + "\n" + format(d.value); });

// add in the title for the nodes
  node.append("text")
      .attr("x", -6)
      .attr("y", function(d) { return d.dy / 2; })
      .attr("dy", ".35em")
      .attr("text-anchor", "end")
      .attr("transform", null)
      .text(function(d) { return d.name; })
    .filter(function(d) { return d.x < width / 2; })
      .attr("x", 6 + sankey.nodeWidth())
      .attr("text-anchor", "start");

// the function for moving the nodes
  function dragmove(d) {
    d3.select(this).attr("transform",
        "translate(" + d.x + "," + (
                d.y = Math.max(0, Math.min(height - d.dy, d3.event.y))
            ) + ")");
    sankey.relayout();
    link.attr("d", path);
  }
});

</script>

</body>
</html>

## sankey.csv

          
            source
            target
            value

            
              Personal income tax
              Income taxes
              142.7

            
              Corporate income tax
              Income taxes
              38.8

            
              Non-resident income tax
              Income taxes
              6.3

            
              Income taxes
              Tax Revenue
              187.8

            
              Goods and Services Tax
              Excise taxes and duties
              33.1

            
              Customs import duties
              Excise taxes and duties
              5.2

            
              Other excise taxes/duties
              Excise taxes and duties
              11.5

            
              Excise taxes and duties
              Tax Revenue
              49.8

            
              Tax Revenue
              Revenue
              237.6

            
              EI  premiums
              Revenue
              23

            
              Crown corporations
              Other Revenue
              13.1

            
              Other programs
              Other Revenue
              15.5

            
              Net foreign exchange
              Other Revenue
              2.1

            
              Other Revenue
              Revenue
              30.6

            
              Transfers to persons
              Elderly benefits
              45.6

            
              Transfers to persons
              EI benefits
              19.4

            
              Transfers to persons
              Childrens benefits
              18.1

            
              Expenses
              Transfers to persons
              83.1

            
              Transfers to governments
              Canada Health Transfer
              34

            
              Canada Health Transfer
              NFLD
              0.528

            
              Canada Health Transfer
              PEI
              0.147

            
              Canada Health Transfer
              NS
              0.943

            
              Canada Health Transfer
              NB
              0.754

            
              Canada Health Transfer
              QU
              8.3

            
              Canada Health Transfer
              ON
              13.867

            
              Canada Health Transfer
              MB
              1.304

            
              Canada Health Transfer
              SK
              1.145

            
              Canada Health Transfer
              AB
              4.245

            
              Canada Health Transfer
              BC
              4.716

            
              Canada Health Transfer
              YT
              0.038

            
              Canada Health Transfer
              NWT
              0.044

            
              Canada Health Transfer
              NVT
              0.037

            
              Canada Social Transfer
              NFLD
              0.195

            
              Canada Social Transfer
              PEI
              0.054

            
              Canada Social Transfer
              NS
              0.349

            
              Canada Social Transfer
              NB
              0.279

            
              Canada Social Transfer
              QU
              3

            
              Canada Social Transfer
              ON
              0.013867

            
              Canada Social Transfer
              MB
              5

            
              Canada Social Transfer
              SK
              0.424

            
              Canada Social Transfer
              AB
              2

            
              Canada Social Transfer
              BC
              2

            
              Canada Social Transfer
              YT
              0.014

            
              Canada Social Transfer
              NWT
              0.016

            
              Canada Social Transfer
              NVT
              0.014

            
              Equalization
              PEI
              .38

            
              Equalization
              NS
              1.722

            
              Equalization
              NB
              1.708

            
              Equalization
              QU
              10.3

            
              Equalization
              ON
              2.304

            
              Equalization
              MB
              .38

            
              Territorial Formula Financing
              YT
              0.895

            
              Territorial Formula Financing
              NWT
              1.22

            
              Territorial Formula Financing
              NVT
              1.489

            
              Offshore Offset Payment
              NS
              .049

            
              Transfers to governments
              Canada Social Transfer
              13

            
              Transfers to governments
              Equalization
              17.3

            
              Transfers to governments
              Territorial Formula Financing
              3.6

            
              Transfers to governments
              Gas Tax Fund
              2

            
              Transfers to governments
              Other fiscal arrangements
              -4

            
              Expenses
              Transfers to governments
              65.8

            
              Direct program expenses
              Transfer payments
              34.1

            
              Direct program expenses
              Capital amortization
              5.2

            
              Direct program expenses
              Operating expenses
              82.8

            
              Expenses
              Direct program expenses
              122

            
              Expenses
              Public debt charges
              25.7

            
              Revenue
              Expenses
              291.2

            
              Deficit
              Expenses
              5.4

## sankey.js
d3.sankey = function() {
  var sankey = {},
      nodeWidth = 24,
      nodePadding = 8,
      size = [1, 1],
      nodes = [],
      links = [];

  sankey.nodeWidth = function(_) {
    if (!arguments.length) return nodeWidth;
    nodeWidth = +_;
    return sankey;
  };

  sankey.nodePadding = function(_) {
    if (!arguments.length) return nodePadding;
    nodePadding = +_;
    return sankey;
  };

  sankey.nodes = function(_) {
    if (!arguments.length) return nodes;
    nodes = _;
    return sankey;
  };

  sankey.links = function(_) {
    if (!arguments.length) return links;
    links = _;
    return sankey;
  };

  sankey.size = function(_) {
    if (!arguments.length) return size;
    size = _;
    return sankey;
  };

  sankey.layout = function(iterations) {
    computeNodeLinks();
    computeNodeValues();
    computeNodeBreadths();
    computeNodeDepths(iterations);
    computeLinkDepths();
    return sankey;
  };

  sankey.relayout = function() {
    computeLinkDepths();
    return sankey;
  };

  sankey.link = function() {
    var curvature = .5;

    function link(d) {
      var x0 = d.source.x + d.source.dx,
          x1 = d.target.x,
          xi = d3.interpolateNumber(x0, x1),
          x2 = xi(curvature),
          x3 = xi(1 - curvature),
          y0 = d.source.y + d.sy + d.dy / 2,
          y1 = d.target.y + d.ty + d.dy / 2;
      return "M" + x0 + "," + y0
           + "C" + x2 + "," + y0
           + " " + x3 + "," + y1
           + " " + x1 + "," + y1;
    }

    link.curvature = function(_) {
      if (!arguments.length) return curvature;
      curvature = +_;
      return link;
    };

    return link;
  };

  // Populate the sourceLinks and targetLinks for each node.
  // Also, if the source and target are not objects, assume they are indices.
  function computeNodeLinks() {
    nodes.forEach(function(node) {
      node.sourceLinks = [];
      node.targetLinks = [];
    });
    links.forEach(function(link) {
      var source = link.source,
          target = link.target;
      if (typeof source === "number") source = link.source = nodes[link.source];
      if (typeof target === "number") target = link.target = nodes[link.target];
      source.sourceLinks.push(link);
      target.targetLinks.push(link);
    });
  }

  // Compute the value (size) of each node by summing the associated links.
  function computeNodeValues() {
    nodes.forEach(function(node) {
      node.value = Math.max(
        d3.sum(node.sourceLinks, value),
        d3.sum(node.targetLinks, value)
      );
    });
  }

  // Iteratively assign the breadth (x-position) for each node.
  // Nodes are assigned the maximum breadth of incoming neighbors plus one;
  // nodes with no incoming links are assigned breadth zero, while
  // nodes with no outgoing links are assigned the maximum breadth.
  function computeNodeBreadths() {
    var remainingNodes = nodes,
        nextNodes,
        x = 0;

    while (remainingNodes.length) {
      nextNodes = [];
      remainingNodes.forEach(function(node) {
        node.x = x;
        node.dx = nodeWidth;
        node.sourceLinks.forEach(function(link) {
          nextNodes.push(link.target);
        });
      });
      remainingNodes = nextNodes;
      ++x;
    }

    //
    moveSinksRight(x);
    scaleNodeBreadths((width - nodeWidth) / (x - 1));
  }

  function moveSourcesRight() {
    nodes.forEach(function(node) {
      if (!node.targetLinks.length) {
        node.x = d3.min(node.sourceLinks, function(d) { return d.target.x; }) - 1;
      }
    });
  }

  function moveSinksRight(x) {
    nodes.forEach(function(node) {
      if (!node.sourceLinks.length) {
        node.x = x - 1;
      }
    });
  }

  function scaleNodeBreadths(kx) {
    nodes.forEach(function(node) {
      node.x *= kx;
    });
  }

  function computeNodeDepths(iterations) {
    var nodesByBreadth = d3.nest()
        .key(function(d) { return d.x; })
        .sortKeys(d3.ascending)
        .entries(nodes)
        .map(function(d) { return d.values; });

    //
    initializeNodeDepth();
    resolveCollisions();
    for (var alpha = 1; iterations > 0; --iterations) {
      relaxRightToLeft(alpha *= .99);
      resolveCollisions();
      relaxLeftToRight(alpha);
      resolveCollisions();
    }

    function initializeNodeDepth() {
      var ky = d3.min(nodesByBreadth, function(nodes) {
        return (size[1] - (nodes.length - 1) * nodePadding) / d3.sum(nodes, value);
      });

      nodesByBreadth.forEach(function(nodes) {
        nodes.forEach(function(node, i) {
          node.y = i;
          node.dy = node.value * ky;
        });
      });

      links.forEach(function(link) {
        link.dy = link.value * ky;
      });
    }

    function relaxLeftToRight(alpha) {
      nodesByBreadth.forEach(function(nodes, breadth) {
        nodes.forEach(function(node) {
          if (node.targetLinks.length) {
            var y = d3.sum(node.targetLinks, weightedSource) / d3.sum(node.targetLinks, value);
            node.y += (y - center(node)) * alpha;
          }
        });
      });

      function weightedSource(link) {
        return center(link.source) * link.value;
      }
    }

    function relaxRightToLeft(alpha) {
      nodesByBreadth.slice().reverse().forEach(function(nodes) {
        nodes.forEach(function(node) {
          if (node.sourceLinks.length) {
            var y = d3.sum(node.sourceLinks, weightedTarget) / d3.sum(node.sourceLinks, value);
            node.y += (y - center(node)) * alpha;
          }
        });
      });

      function weightedTarget(link) {
        return center(link.target) * link.value;
      }
    }

    function resolveCollisions() {
      nodesByBreadth.forEach(function(nodes) {
        var node,
            dy,
            y0 = 0,
            n = nodes.length,
            i;

        // Push any overlapping nodes down.
        nodes.sort(ascendingDepth);
        for (i = 0; i < n; ++i) {
          node = nodes[i];
          dy = y0 - node.y;
          if (dy > 0) node.y += dy;
          y0 = node.y + node.dy + nodePadding;
        }

        // If the bottommost node goes outside the bounds, push it back up.
        dy = y0 - nodePadding - size[1];
        if (dy > 0) {
          y0 = node.y -= dy;

          // Push any overlapping nodes back up.
          for (i = n - 2; i >= 0; --i) {
            node = nodes[i];
            dy = node.y + node.dy + nodePadding - y0;
            if (dy > 0) node.y -= dy;
            y0 = node.y;
          }
        }
      });
    }

    function ascendingDepth(a, b) {
      return a.y - b.y;
    }
  }

  function computeLinkDepths() {
    nodes.forEach(function(node) {
      node.sourceLinks.sort(ascendingTargetDepth);
      node.targetLinks.sort(ascendingSourceDepth);
    });
    nodes.forEach(function(node) {
      var sy = 0, ty = 0;
      node.sourceLinks.forEach(function(link) {
        link.sy = sy;
        sy += link.dy;
      });
      node.targetLinks.forEach(function(link) {
        link.ty = ty;
        ty += link.dy;
      });
    });

    function ascendingSourceDepth(a, b) {
      return a.source.y - b.source.y;
    }

    function ascendingTargetDepth(a, b) {
      return a.target.y - b.target.y;
    }
  }

  function center(node) {
    return node.y + node.dy / 2;
  }

  function value(link) {
    return link.value;
  }

  return sankey;
};
	<!DOCTYPE html>
	<meta charset="utf-8">
	<title>Canada Budget 2016</title>
	<style>

	.node rect {
	cursor: move;
	fill-opacity: .9;
	shape-rendering: crispEdges;
	}

	.node text {
	pointer-events: none;
	text-shadow: 0 1px 0 #fff;
	}

	.link {
	fill: none;
	stroke: #000;
	stroke-opacity: .2;
	}

	.link:hover {
	stroke-opacity: .5;
	}

	</style>
	<body>

	<p id="chart">

	<script src="http://d3js.org/d3.v3.min.js"></script>
	<script src="sankey.js"></script>
	<script>

	var units = "billions";

	var margin = {top: 10, right: 10, bottom: 10, left: 10},
	width = 1000 - margin.left - margin.right,
	height = 800 - margin.top - margin.bottom;

	var formatNumber = d3.format(",.0f"), // zero decimal places
	format = function(d) { return formatNumber(d) + " " + units; },
	color = d3.scale.category20();

	// append the svg canvas to the page
	var svg = d3.select("#chart").append("svg")
	.attr("width", width + margin.left + margin.right)
	.attr("height", height + margin.top + margin.bottom)
	.append("g")
	.attr("transform",
	"translate(" + margin.left + "," + margin.top + ")");

	// Set the sankey diagram properties
	var sankey = d3.sankey()
	.nodeWidth(9)
	.nodePadding(10)
	.size([width, height]);

	var path = sankey.link();

	// load the data (using the timelyportfolio csv method)
	d3.csv("sankey.csv", function(error, data) {

	//set up graph in same style as original example but empty
	graph = {"nodes" : [], "links" : []};

	data.forEach(function (d) {
	graph.nodes.push({ "name": d.source });
	graph.nodes.push({ "name": d.target });
	graph.links.push({ "source": d.source,
	"target": d.target,
	"value": +d.value });
	});

	// return only the distinct / unique nodes
	graph.nodes = d3.keys(d3.nest()
	.key(function (d) { return d.name; })
	.map(graph.nodes));

	// loop through each link replacing the text with its index from node
	graph.links.forEach(function (d, i) {
	graph.links[i].source = graph.nodes.indexOf(graph.links[i].source);
	graph.links[i].target = graph.nodes.indexOf(graph.links[i].target);
	});

	//now loop through each nodes to make nodes an array of objects
	// rather than an array of strings
	graph.nodes.forEach(function (d, i) {
	graph.nodes[i] = { "name": d };
	});

	sankey
	.nodes(graph.nodes)
	.links(graph.links)
	.layout(32);

	// add in the links
	var link = svg.append("g").selectAll(".link")
	.data(graph.links)
	.enter().append("path")
	.attr("class", "link")
	.attr("d", path)
	.style("stroke-width", function(d) { return Math.max(1, d.dy); })
	.sort(function(a, b) { return b.dy - a.dy; });

	// add the link titles
	link.append("title")
	.text(function(d) {
	return d.source.name + " → " +
	d.target.name + "\n" + format(d.value); });

	// add in the nodes
	var node = svg.append("g").selectAll(".node")
	.data(graph.nodes)
	.enter().append("g")
	.attr("class", "node")
	.attr("transform", function(d) {
	return "translate(" + d.x + "," + d.y + ")"; })
	.call(d3.behavior.drag()
	.origin(function(d) { return d; })
	.on("dragstart", function() {
	this.parentNode.appendChild(this); })
	.on("drag", dragmove));

	// add the rectangles for the nodes
	node.append("rect")
	.attr("height", function(d) { return d.dy; })
	.attr("width", sankey.nodeWidth())
	.style("fill", function(d) {
	return d.color = color(d.name.replace(/ .*/, "")); })
	.style("stroke", function(d) {
	return d3.rgb(d.color).darker(2); })
	.append("title")
	.text(function(d) {
	return d.name + "\n" + format(d.value); });

	// add in the title for the nodes
	node.append("text")
	.attr("x", -6)
	.attr("y", function(d) { return d.dy / 2; })
	.attr("dy", ".35em")
	.attr("text-anchor", "end")
	.attr("transform", null)
	.text(function(d) { return d.name; })
	.filter(function(d) { return d.x < width / 2; })
	.attr("x", 6 + sankey.nodeWidth())
	.attr("text-anchor", "start");

	// the function for moving the nodes
	function dragmove(d) {
	d3.select(this).attr("transform",
	"translate(" + d.x + "," + (
	d.y = Math.max(0, Math.min(height - d.dy, d3.event.y))
	) + ")");
	sankey.relayout();
	link.attr("d", path);
	}
	});

	</script>

	</body>
	</html>
source	target	value
Personal income tax	Income taxes	142.7
Corporate income tax	Income taxes	38.8
Non-resident income tax	Income taxes	6.3
Income taxes	Tax Revenue	187.8
Goods and Services Tax	Excise taxes and duties	33.1
Customs import duties	Excise taxes and duties	5.2
Other excise taxes/duties	Excise taxes and duties	11.5
Excise taxes and duties	Tax Revenue	49.8
Tax Revenue	Revenue	237.6
EI premiums	Revenue	23
Crown corporations	Other Revenue	13.1
Other programs	Other Revenue	15.5
Net foreign exchange	Other Revenue	2.1
Other Revenue	Revenue	30.6
Transfers to persons	Elderly benefits	45.6
Transfers to persons	EI benefits	19.4
Transfers to persons	Childrens benefits	18.1
Expenses	Transfers to persons	83.1
Transfers to governments	Canada Health Transfer	34
Canada Health Transfer	NFLD	0.528
Canada Health Transfer	PEI	0.147
Canada Health Transfer	NS	0.943
Canada Health Transfer	NB	0.754
Canada Health Transfer	QU	8.3
Canada Health Transfer	ON	13.867
Canada Health Transfer	MB	1.304
Canada Health Transfer	SK	1.145
Canada Health Transfer	AB	4.245
Canada Health Transfer	BC	4.716
Canada Health Transfer	YT	0.038
Canada Health Transfer	NWT	0.044
Canada Health Transfer	NVT	0.037
Canada Social Transfer	NFLD	0.195
Canada Social Transfer	PEI	0.054
Canada Social Transfer	NS	0.349
Canada Social Transfer	NB	0.279
Canada Social Transfer	QU	3
Canada Social Transfer	ON	0.013867
Canada Social Transfer	MB	5
Canada Social Transfer	SK	0.424
Canada Social Transfer	AB	2
Canada Social Transfer	BC	2
Canada Social Transfer	YT	0.014
Canada Social Transfer	NWT	0.016
Canada Social Transfer	NVT	0.014
Equalization	PEI	.38
Equalization	NS	1.722
Equalization	NB	1.708
Equalization	QU	10.3
Equalization	ON	2.304
Equalization	MB	.38
Territorial Formula Financing	YT	0.895
Territorial Formula Financing	NWT	1.22
Territorial Formula Financing	NVT	1.489
Offshore Offset Payment	NS	.049
Transfers to governments	Canada Social Transfer	13
Transfers to governments	Equalization	17.3
Transfers to governments	Territorial Formula Financing	3.6
Transfers to governments	Gas Tax Fund	2
Transfers to governments	Other fiscal arrangements	-4
Expenses	Transfers to governments	65.8
Direct program expenses	Transfer payments	34.1
Direct program expenses	Capital amortization	5.2
Direct program expenses	Operating expenses	82.8
Expenses	Direct program expenses	122
Expenses	Public debt charges	25.7
Revenue	Expenses	291.2
Deficit	Expenses	5.4
	d3.sankey = function() {
	var sankey = {},
	nodeWidth = 24,
	nodePadding = 8,
	size = [1, 1],
	nodes = [],
	links = [];

	sankey.nodeWidth = function(_) {
	if (!arguments.length) return nodeWidth;
	nodeWidth = +_;
	return sankey;
	};

	sankey.nodePadding = function(_) {
	if (!arguments.length) return nodePadding;
	nodePadding = +_;
	return sankey;
	};

	sankey.nodes = function(_) {
	if (!arguments.length) return nodes;
	nodes = _;
	return sankey;
	};

	sankey.links = function(_) {
	if (!arguments.length) return links;
	links = _;
	return sankey;
	};

	sankey.size = function(_) {
	if (!arguments.length) return size;
	size = _;
	return sankey;
	};

	sankey.layout = function(iterations) {
	computeNodeLinks();
	computeNodeValues();
	computeNodeBreadths();
	computeNodeDepths(iterations);
	computeLinkDepths();
	return sankey;
	};

	sankey.relayout = function() {
	computeLinkDepths();
	return sankey;
	};

	sankey.link = function() {
	var curvature = .5;

	function link(d) {
	var x0 = d.source.x + d.source.dx,
	x1 = d.target.x,
	xi = d3.interpolateNumber(x0, x1),
	x2 = xi(curvature),
	x3 = xi(1 - curvature),
	y0 = d.source.y + d.sy + d.dy / 2,
	y1 = d.target.y + d.ty + d.dy / 2;
	return "M" + x0 + "," + y0
	+ "C" + x2 + "," + y0
	+ " " + x3 + "," + y1
	+ " " + x1 + "," + y1;
	}

	link.curvature = function(_) {
	if (!arguments.length) return curvature;
	curvature = +_;
	return link;
	};

	return link;
	};

	// Populate the sourceLinks and targetLinks for each node.
	// Also, if the source and target are not objects, assume they are indices.
	function computeNodeLinks() {
	nodes.forEach(function(node) {
	node.sourceLinks = [];
	node.targetLinks = [];
	});
	links.forEach(function(link) {
	var source = link.source,
	target = link.target;
	if (typeof source === "number") source = link.source = nodes[link.source];
	if (typeof target === "number") target = link.target = nodes[link.target];
	source.sourceLinks.push(link);
	target.targetLinks.push(link);
	});
	}

	// Compute the value (size) of each node by summing the associated links.
	function computeNodeValues() {
	nodes.forEach(function(node) {
	node.value = Math.max(
	d3.sum(node.sourceLinks, value),
	d3.sum(node.targetLinks, value)
	);
	});
	}

	// Iteratively assign the breadth (x-position) for each node.
	// Nodes are assigned the maximum breadth of incoming neighbors plus one;
	// nodes with no incoming links are assigned breadth zero, while
	// nodes with no outgoing links are assigned the maximum breadth.
	function computeNodeBreadths() {
	var remainingNodes = nodes,
	nextNodes,
	x = 0;

	while (remainingNodes.length) {
	nextNodes = [];
	remainingNodes.forEach(function(node) {
	node.x = x;
	node.dx = nodeWidth;
	node.sourceLinks.forEach(function(link) {
	nextNodes.push(link.target);
	});
	});
	remainingNodes = nextNodes;
	++x;
	}

	//
	moveSinksRight(x);
	scaleNodeBreadths((width - nodeWidth) / (x - 1));
	}

	function moveSourcesRight() {
	nodes.forEach(function(node) {
	if (!node.targetLinks.length) {
	node.x = d3.min(node.sourceLinks, function(d) { return d.target.x; }) - 1;
	}
	});
	}

	function moveSinksRight(x) {
	nodes.forEach(function(node) {
	if (!node.sourceLinks.length) {
	node.x = x - 1;
	}
	});
	}

	function scaleNodeBreadths(kx) {
	nodes.forEach(function(node) {
	node.x *= kx;
	});
	}

	function computeNodeDepths(iterations) {
	var nodesByBreadth = d3.nest()
	.key(function(d) { return d.x; })
	.sortKeys(d3.ascending)
	.entries(nodes)
	.map(function(d) { return d.values; });

	//
	initializeNodeDepth();
	resolveCollisions();
	for (var alpha = 1; iterations > 0; --iterations) {
	relaxRightToLeft(alpha *= .99);
	resolveCollisions();
	relaxLeftToRight(alpha);
	resolveCollisions();
	}

	function initializeNodeDepth() {
	var ky = d3.min(nodesByBreadth, function(nodes) {
	return (size[1] - (nodes.length - 1) * nodePadding) / d3.sum(nodes, value);
	});

	nodesByBreadth.forEach(function(nodes) {
	nodes.forEach(function(node, i) {
	node.y = i;
	node.dy = node.value * ky;
	});
	});

	links.forEach(function(link) {
	link.dy = link.value * ky;
	});
	}

	function relaxLeftToRight(alpha) {
	nodesByBreadth.forEach(function(nodes, breadth) {
	nodes.forEach(function(node) {
	if (node.targetLinks.length) {
	var y = d3.sum(node.targetLinks, weightedSource) / d3.sum(node.targetLinks, value);
	node.y += (y - center(node)) * alpha;
	}
	});
	});

	function weightedSource(link) {
	return center(link.source) * link.value;
	}
	}

	function relaxRightToLeft(alpha) {
	nodesByBreadth.slice().reverse().forEach(function(nodes) {
	nodes.forEach(function(node) {
	if (node.sourceLinks.length) {
	var y = d3.sum(node.sourceLinks, weightedTarget) / d3.sum(node.sourceLinks, value);
	node.y += (y - center(node)) * alpha;
	}
	});
	});

	function weightedTarget(link) {
	return center(link.target) * link.value;
	}
	}

	function resolveCollisions() {
	nodesByBreadth.forEach(function(nodes) {
	var node,
	dy,
	y0 = 0,
	n = nodes.length,
	i;

	// Push any overlapping nodes down.
	nodes.sort(ascendingDepth);
	for (i = 0; i < n; ++i) {
	node = nodes[i];
	dy = y0 - node.y;
	if (dy > 0) node.y += dy;
	y0 = node.y + node.dy + nodePadding;
	}

	// If the bottommost node goes outside the bounds, push it back up.
	dy = y0 - nodePadding - size[1];
	if (dy > 0) {
	y0 = node.y -= dy;

	// Push any overlapping nodes back up.
	for (i = n - 2; i >= 0; --i) {
	node = nodes[i];
	dy = node.y + node.dy + nodePadding - y0;
	if (dy > 0) node.y -= dy;
	y0 = node.y;
	}
	}
	});
	}

	function ascendingDepth(a, b) {
	return a.y - b.y;
	}
	}

	function computeLinkDepths() {
	nodes.forEach(function(node) {
	node.sourceLinks.sort(ascendingTargetDepth);
	node.targetLinks.sort(ascendingSourceDepth);
	});
	nodes.forEach(function(node) {
	var sy = 0, ty = 0;
	node.sourceLinks.forEach(function(link) {
	link.sy = sy;
	sy += link.dy;
	});
	node.targetLinks.forEach(function(link) {
	link.ty = ty;
	ty += link.dy;
	});
	});

	function ascendingSourceDepth(a, b) {
	return a.source.y - b.source.y;
	}

	function ascendingTargetDepth(a, b) {
	return a.target.y - b.target.y;
	}
	}

	function center(node) {
	return node.y + node.dy / 2;
	}

	function value(link) {
	return link.value;
	}

	return sankey;
	};