block by michalskop 5508877

Sankey presidential chart

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index.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>Sankey Diagram</title>
<style>

#chart {
  height: 500px;
}

.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>

<header>
  <aside>May 03, 2013</aside>
  <a href="../" rel="author">Michal Škop</a>
</header>

<h1>Voters shifts between 1st and 2nd round of Czech presidential elections 2013</h1>

<p id="chart">

<aside>Drag to rearrange nodes.</aside>

<p>Based on <a href="//bost.ocks.org/mike/sankey/">Mike Bostock's Sankey Diagrams</a>. It uses data from <a href="//data.blog.ihned.cz/c1-59198510-vysledky-druhe-kolo-data">Kamil Gregor's computations</a>.</p>

<script src="//d3js.org/d3.v2.min.js?2.9.1"></script>
<script src="sankey.js"></script>
<script>

var margin = {top: 1, right: 1, bottom: 6, left: 1},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;

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

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 + ")");

var sankey = d3.sankey()
    .nodeWidth(15)
    .nodePadding(10)
    .size([width, height]);

var path = sankey.link();

d3.json("sankey.json", function(energy) {

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

  var link = svg.append("g").selectAll(".link")
      .data(energy.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; });

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

  var node = svg.append("g").selectAll(".node")
      .data(energy.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));

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

  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");

  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>

readme.rm

Sankey diagram of estimates of voters shifts between 1st and 2nd round of Czech presidential elections 2013.

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;
};

sankey.json

{"nodes":[{"name":"Zeman","color":"#FF0000"},{"name":"Schwarzenberg","color":"#880088"},{"name":"Fischer","color":"#0000FF"},{"name":"Dienstbier","color":"#FFA500"},{"name":"Franz","color":"#000000"},{"name":"Roithov\u00e1","color":"#FFFF00"},{"name":"Fischerov\u00e1","color":"#00AA00"},{"name":"Sobotka","color":"#000088"},{"name":"Bobo\u0161\u00edkov\u00e1","color":"#FFFF44"},{"name":"Nevoli\u010di","color":"#808080"},{"name":"Zeman II","color":"#FF0000"},{"name":"Schwarzenberg II","color":"#880088"},{"name":"Nevoli\u010di II","color":"#808080"}],"links":[{"source":0,"target":12,"value":3},{"source":1,"target":12,"value":2},{"source":2,"target":12,"value":4},{"source":3,"target":12,"value":2},{"source":4,"target":12,"value":2},{"source":6,"target":12,"value":1},{"source":8,"target":12,"value":1},{"source":9,"target":12,"value":26},{"source":0,"target":10,"value":13},{"source":2,"target":10,"value":5},{"source":3,"target":10,"value":7},{"source":4,"target":10,"value":1},{"source":5,"target":10,"value":2},{"source":8,"target":10,"value":1},{"source":9,"target":10,"value":4},{"source":1,"target":11,"value":12},{"source":2,"target":11,"value":3},{"source":3,"target":11,"value":1},{"source":4,"target":11,"value":2},{"source":5,"target":11,"value":2},{"source":6,"target":11,"value":1},{"source":7,"target":11,"value":1},{"source":9,"target":11,"value":4}]}

sankey.php

<?php

$ar = array(
  'nodes' => array(
    array('name'=>'Zeman','color'=>'#FF0000'),
    array('name'=>'Schwarzenberg','color'=>'#880088'),
    array('name'=>'Fischer','color'=>'#0000FF'),
    array('name'=>'Dienstbier','color'=>'#FFA500'),
    array('name'=>'Franz','color'=>'#000000'),
    array('name'=>'Roithová','color'=>'#FFFF00'),
    array('name'=>'Fischerová','color'=>'#00AA00'),
    array('name'=>'Sobotka','color'=>'#000088'),
    array('name'=>'Bobošíková','color'=>'#FFFF44'),
    array('name'=>'Nevoliči','color'=>'#808080'),
    array('name'=>'Zeman II','color'=>'#FF0000'),
    array('name'=>'Schwarzenberg II','color'=>'#880088'),
    array('name'=>'Nevoliči II','color'=>'#808080'),
  ),
  'links' => array(
    array('source'=>0,'target'=>12,'value'=>3),
    array('source'=>1,'target'=>12,'value'=>2),
    array('source'=>2,'target'=>12,'value'=>4),
    array('source'=>3,'target'=>12,'value'=>2),
    array('source'=>4,'target'=>12,'value'=>2),
    //array('source'=>5,'target'=>12,'value'=>0),
    array('source'=>6,'target'=>12,'value'=>1),
    //array('source'=>7,'target'=>12,'value'=>0),
    array('source'=>8,'target'=>12,'value'=>1),
    array('source'=>9,'target'=>12,'value'=>26),

    array('source'=>0,'target'=>10,'value'=>13),
    //array('source'=>1,'target'=>10,'value'=>0),
    array('source'=>2,'target'=>10,'value'=>5),
    array('source'=>3,'target'=>10,'value'=>7),
    array('source'=>4,'target'=>10,'value'=>1),
    array('source'=>5,'target'=>10,'value'=>2),
    //array('source'=>6,'target'=>10,'value'=>0),
    //array('source'=>7,'target'=>10,'value'=>0),
    array('source'=>8,'target'=>10,'value'=>1),
    array('source'=>9,'target'=>10,'value'=>4),
    
    //array('source'=>0,'target'=>11,'value'=>0),
    array('source'=>1,'target'=>11,'value'=>12),
    array('source'=>2,'target'=>11,'value'=>3),
    array('source'=>3,'target'=>11,'value'=>1),
    array('source'=>4,'target'=>11,'value'=>2),
    array('source'=>5,'target'=>11,'value'=>2),
    array('source'=>6,'target'=>11,'value'=>1),
    array('source'=>7,'target'=>11,'value'=>1),
    //array('source'=>8,'target'=>11,'value'=>0),
    array('source'=>9,'target'=>11,'value'=>4),
  ),
);

echo json_encode($ar);
?>