D3js and Web Audio API

.block

licence: mit

README.md

More experiments with audio and D3js. The idea was reproducing the famous cover by Joy Division, animating it with the music.

Since the regular frequencyData data is too flat to get a nice result, I calculate the difference with the previous values, so it gives nice peaks. The graph means more or less nothing!

The music is taken from this site, because it's free (and I liked this one). It's a pitty not using the original album:

http://freemusicarchive.org/music/The_Orientalist/1000_Sounds_Lotus/Islamatronic_cantilliation_1461

I took information from these pages aboud web audio:

• http://bl.ocks.org/eesur/6ad4ee84c81b664353a7
• https://www.bignerdranch.com/blog/music-visualization-with-d3-js/

To create the app.js file, just run

browserify index.js > app.js

app.js

(function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){

var d3_shape = require("d3-shape");
var d3_selection = require("d3-selection");

var width = 500;
var height = 500;
var dataPerLine = 30;
var lines = 60;
var playing = false;

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
    var audioElement = document.getElementById('audioElement');
    var audioSrc = audioCtx.createMediaElementSource(audioElement);
    var analyser = audioCtx.createAnalyser();

    audioSrc.connect(analyser);
    audioSrc.connect(audioCtx.destination);

    var frequencyData = new Uint8Array(lines);


var canvas = d3_selection.select("body")
    .append("canvas")
    .attr('height', height)
    .attr('width', width);

var context = canvas.node().getContext("2d");

var line = d3_shape.line()
    .x(function(d, i){return width/4 + (i/dataPerLine)*width/2;})
    .y(function(d, i){return -d * Math.sin(Math.PI * i/dataPerLine);})
    .context(context);

var area = d3_shape.area()
    .x(function(d, i){return width/4 + (i/dataPerLine)*width/2;})
    .y1(function(d, i){return -d * Math.sin(Math.PI * i/dataPerLine);})
    .y0(40)
    .context(context);


var data = [];
for (var i = 0; i < lines; i++) {
    var dataElements = [];
    for (var j = 0; j < dataPerLine; j++) {
        dataElements.push(0);
    }
    data.push(dataElements);
  }

 

function renderChart() {
     requestAnimationFrame(renderChart);

     // Copy frequency data to frequencyData array.
     analyser.getByteFrequencyData(frequencyData);
     for(var i = 0; i < lines; i++){
         data[i].push(frequencyData[i]);
         data[i].shift();
     }

    
    context.fillStyle = "black";
    context.fillRect(0, 0, width, height);

    context.lineWidth = 1.6;
    context.strokeStyle = "#dddddd";
    context.fillStyle = "#000000";
    for(var i = 0; i < lines; i++){
            context.save();

            context.translate(0,((height/5) + (i/lines)*3*height/5));
            context.beginPath();
            area(data[i].map(function(curr, i, arr){return i>0?curr - arr[i-1]:0;}));
            context.fill();
            context.beginPath();
            line(data[i].map(function(curr, i, arr){return i>0?curr - arr[i-1]:0;}));
            context.stroke();


            context.restore();
        }

  }

  // Run the loop
  renderChart();
 
  canvas.on("click", togglePlay);
  

  function togglePlay(){
    if(playing===false){
        audioElement.play();
        playing = true;
    } else {
        audioElement.pause();
        playing = false;
    }
  }

  togglePlay();
  
},{"d3-selection":3,"d3-shape":4}],2:[function(require,module,exports){
// https://d3js.org/d3-path/ Version 1.0.5. Copyright 2017 Mike Bostock.
(function (global, factory) {
	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
	typeof define === 'function' && define.amd ? define(['exports'], factory) :
	(factory((global.d3 = global.d3 || {})));
}(this, (function (exports) { 'use strict';

var pi = Math.PI;
var tau = 2 * pi;
var epsilon = 1e-6;
var tauEpsilon = tau - epsilon;

function Path() {
  this._x0 = this._y0 = // start of current subpath
  this._x1 = this._y1 = null; // end of current subpath
  this._ = "";
}

function path() {
  return new Path;
}

Path.prototype = path.prototype = {
  constructor: Path,
  moveTo: function(x, y) {
    this._ += "M" + (this._x0 = this._x1 = +x) + "," + (this._y0 = this._y1 = +y);
  },
  closePath: function() {
    if (this._x1 !== null) {
      this._x1 = this._x0, this._y1 = this._y0;
      this._ += "Z";
    }
  },
  lineTo: function(x, y) {
    this._ += "L" + (this._x1 = +x) + "," + (this._y1 = +y);
  },
  quadraticCurveTo: function(x1, y1, x, y) {
    this._ += "Q" + (+x1) + "," + (+y1) + "," + (this._x1 = +x) + "," + (this._y1 = +y);
  },
  bezierCurveTo: function(x1, y1, x2, y2, x, y) {
    this._ += "C" + (+x1) + "," + (+y1) + "," + (+x2) + "," + (+y2) + "," + (this._x1 = +x) + "," + (this._y1 = +y);
  },
  arcTo: function(x1, y1, x2, y2, r) {
    x1 = +x1, y1 = +y1, x2 = +x2, y2 = +y2, r = +r;
    var x0 = this._x1,
        y0 = this._y1,
        x21 = x2 - x1,
        y21 = y2 - y1,
        x01 = x0 - x1,
        y01 = y0 - y1,
        l01_2 = x01 * x01 + y01 * y01;

    // Is the radius negative? Error.
    if (r < 0) throw new Error("negative radius: " + r);

    // Is this path empty? Move to (x1,y1).
    if (this._x1 === null) {
      this._ += "M" + (this._x1 = x1) + "," + (this._y1 = y1);
    }

    // Or, is (x1,y1) coincident with (x0,y0)? Do nothing.
    else if (!(l01_2 > epsilon)) {}

    // Or, are (x0,y0), (x1,y1) and (x2,y2) collinear?
    // Equivalently, is (x1,y1) coincident with (x2,y2)?
    // Or, is the radius zero? Line to (x1,y1).
    else if (!(Math.abs(y01 * x21 - y21 * x01) > epsilon) || !r) {
      this._ += "L" + (this._x1 = x1) + "," + (this._y1 = y1);
    }

    // Otherwise, draw an arc!
    else {
      var x20 = x2 - x0,
          y20 = y2 - y0,
          l21_2 = x21 * x21 + y21 * y21,
          l20_2 = x20 * x20 + y20 * y20,
          l21 = Math.sqrt(l21_2),
          l01 = Math.sqrt(l01_2),
          l = r * Math.tan((pi - Math.acos((l21_2 + l01_2 - l20_2) / (2 * l21 * l01))) / 2),
          t01 = l / l01,
          t21 = l / l21;

      // If the start tangent is not coincident with (x0,y0), line to.
      if (Math.abs(t01 - 1) > epsilon) {
        this._ += "L" + (x1 + t01 * x01) + "," + (y1 + t01 * y01);
      }

      this._ += "A" + r + "," + r + ",0,0," + (+(y01 * x20 > x01 * y20)) + "," + (this._x1 = x1 + t21 * x21) + "," + (this._y1 = y1 + t21 * y21);
    }
  },
  arc: function(x, y, r, a0, a1, ccw) {
    x = +x, y = +y, r = +r;
    var dx = r * Math.cos(a0),
        dy = r * Math.sin(a0),
        x0 = x + dx,
        y0 = y + dy,
        cw = 1 ^ ccw,
        da = ccw ? a0 - a1 : a1 - a0;

    // Is the radius negative? Error.
    if (r < 0) throw new Error("negative radius: " + r);

    // Is this path empty? Move to (x0,y0).
    if (this._x1 === null) {
      this._ += "M" + x0 + "," + y0;
    }

    // Or, is (x0,y0) not coincident with the previous point? Line to (x0,y0).
    else if (Math.abs(this._x1 - x0) > epsilon || Math.abs(this._y1 - y0) > epsilon) {
      this._ += "L" + x0 + "," + y0;
    }

    // Is this arc empty? We’re done.
    if (!r) return;

    // Does the angle go the wrong way? Flip the direction.
    if (da < 0) da = da % tau + tau;

    // Is this a complete circle? Draw two arcs to complete the circle.
    if (da > tauEpsilon) {
      this._ += "A" + r + "," + r + ",0,1," + cw + "," + (x - dx) + "," + (y - dy) + "A" + r + "," + r + ",0,1," + cw + "," + (this._x1 = x0) + "," + (this._y1 = y0);
    }

    // Is this arc non-empty? Draw an arc!
    else if (da > epsilon) {
      this._ += "A" + r + "," + r + ",0," + (+(da >= pi)) + "," + cw + "," + (this._x1 = x + r * Math.cos(a1)) + "," + (this._y1 = y + r * Math.sin(a1));
    }
  },
  rect: function(x, y, w, h) {
    this._ += "M" + (this._x0 = this._x1 = +x) + "," + (this._y0 = this._y1 = +y) + "h" + (+w) + "v" + (+h) + "h" + (-w) + "Z";
  },
  toString: function() {
    return this._;
  }
};

exports.path = path;

Object.defineProperty(exports, '__esModule', { value: true });

})));

},{}],3:[function(require,module,exports){
// https://d3js.org/d3-selection/ Version 1.1.0. Copyright 2017 Mike Bostock.
(function (global, factory) {
	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
	typeof define === 'function' && define.amd ? define(['exports'], factory) :
	(factory((global.d3 = global.d3 || {})));
}(this, (function (exports) { 'use strict';

var xhtml = "http://www.w3.org/1999/xhtml";

var namespaces = {
  svg: "http://www.w3.org/2000/svg",
  xhtml: xhtml,
  xlink: "http://www.w3.org/1999/xlink",
  xml: "http://www.w3.org/XML/1998/namespace",
  xmlns: "http://www.w3.org/2000/xmlns/"
};

var namespace = function(name) {
  var prefix = name += "", i = prefix.indexOf(":");
  if (i >= 0 && (prefix = name.slice(0, i)) !== "xmlns") name = name.slice(i + 1);
  return namespaces.hasOwnProperty(prefix) ? {space: namespaces[prefix], local: name} : name;
};

function creatorInherit(name) {
  return function() {
    var document = this.ownerDocument,
        uri = this.namespaceURI;
    return uri === xhtml && document.documentElement.namespaceURI === xhtml
        ? document.createElement(name)
        : document.createElementNS(uri, name);
  };
}

function creatorFixed(fullname) {
  return function() {
    return this.ownerDocument.createElementNS(fullname.space, fullname.local);
  };
}

var creator = function(name) {
  var fullname = namespace(name);
  return (fullname.local
      ? creatorFixed
      : creatorInherit)(fullname);
};

var nextId = 0;

function local() {
  return new Local;
}

function Local() {
  this._ = "@" + (++nextId).toString(36);
}

Local.prototype = local.prototype = {
  constructor: Local,
  get: function(node) {
    var id = this._;
    while (!(id in node)) if (!(node = node.parentNode)) return;
    return node[id];
  },
  set: function(node, value) {
    return node[this._] = value;
  },
  remove: function(node) {
    return this._ in node && delete node[this._];
  },
  toString: function() {
    return this._;
  }
};

var matcher = function(selector) {
  return function() {
    return this.matches(selector);
  };
};

if (typeof document !== "undefined") {
  var element = document.documentElement;
  if (!element.matches) {
    var vendorMatches = element.webkitMatchesSelector
        || element.msMatchesSelector
        || element.mozMatchesSelector
        || element.oMatchesSelector;
    matcher = function(selector) {
      return function() {
        return vendorMatches.call(this, selector);
      };
    };
  }
}

var matcher$1 = matcher;

var filterEvents = {};

exports.event = null;

if (typeof document !== "undefined") {
  var element$1 = document.documentElement;
  if (!("onmouseenter" in element$1)) {
    filterEvents = {mouseenter: "mouseover", mouseleave: "mouseout"};
  }
}

function filterContextListener(listener, index, group) {
  listener = contextListener(listener, index, group);
  return function(event) {
    var related = event.relatedTarget;
    if (!related || (related !== this && !(related.compareDocumentPosition(this) & 8))) {
      listener.call(this, event);
    }
  };
}

function contextListener(listener, index, group) {
  return function(event1) {
    var event0 = exports.event; // Events can be reentrant (e.g., focus).
    exports.event = event1;
    try {
      listener.call(this, this.__data__, index, group);
    } finally {
      exports.event = event0;
    }
  };
}

function parseTypenames(typenames) {
  return typenames.trim().split(/^|\s+/).map(function(t) {
    var name = "", i = t.indexOf(".");
    if (i >= 0) name = t.slice(i + 1), t = t.slice(0, i);
    return {type: t, name: name};
  });
}

function onRemove(typename) {
  return function() {
    var on = this.__on;
    if (!on) return;
    for (var j = 0, i = -1, m = on.length, o; j < m; ++j) {
      if (o = on[j], (!typename.type || o.type === typename.type) && o.name === typename.name) {
        this.removeEventListener(o.type, o.listener, o.capture);
      } else {
        on[++i] = o;
      }
    }
    if (++i) on.length = i;
    else delete this.__on;
  };
}

function onAdd(typename, value, capture) {
  var wrap = filterEvents.hasOwnProperty(typename.type) ? filterContextListener : contextListener;
  return function(d, i, group) {
    var on = this.__on, o, listener = wrap(value, i, group);
    if (on) for (var j = 0, m = on.length; j < m; ++j) {
      if ((o = on[j]).type === typename.type && o.name === typename.name) {
        this.removeEventListener(o.type, o.listener, o.capture);
        this.addEventListener(o.type, o.listener = listener, o.capture = capture);
        o.value = value;
        return;
      }
    }
    this.addEventListener(typename.type, listener, capture);
    o = {type: typename.type, name: typename.name, value: value, listener: listener, capture: capture};
    if (!on) this.__on = [o];
    else on.push(o);
  };
}

var selection_on = function(typename, value, capture) {
  var typenames = parseTypenames(typename + ""), i, n = typenames.length, t;

  if (arguments.length < 2) {
    var on = this.node().__on;
    if (on) for (var j = 0, m = on.length, o; j < m; ++j) {
      for (i = 0, o = on[j]; i < n; ++i) {
        if ((t = typenames[i]).type === o.type && t.name === o.name) {
          return o.value;
        }
      }
    }
    return;
  }

  on = value ? onAdd : onRemove;
  if (capture == null) capture = false;
  for (i = 0; i < n; ++i) this.each(on(typenames[i], value, capture));
  return this;
};

function customEvent(event1, listener, that, args) {
  var event0 = exports.event;
  event1.sourceEvent = exports.event;
  exports.event = event1;
  try {
    return listener.apply(that, args);
  } finally {
    exports.event = event0;
  }
}

var sourceEvent = function() {
  var current = exports.event, source;
  while (source = current.sourceEvent) current = source;
  return current;
};

var point = function(node, event) {
  var svg = node.ownerSVGElement || node;

  if (svg.createSVGPoint) {
    var point = svg.createSVGPoint();
    point.x = event.clientX, point.y = event.clientY;
    point = point.matrixTransform(node.getScreenCTM().inverse());
    return [point.x, point.y];
  }

  var rect = node.getBoundingClientRect();
  return [event.clientX - rect.left - node.clientLeft, event.clientY - rect.top - node.clientTop];
};

var mouse = function(node) {
  var event = sourceEvent();
  if (event.changedTouches) event = event.changedTouches[0];
  return point(node, event);
};

function none() {}

var selector = function(selector) {
  return selector == null ? none : function() {
    return this.querySelector(selector);
  };
};

var selection_select = function(select) {
  if (typeof select !== "function") select = selector(select);

  for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
    for (var group = groups[j], n = group.length, subgroup = subgroups[j] = new Array(n), node, subnode, i = 0; i < n; ++i) {
      if ((node = group[i]) && (subnode = select.call(node, node.__data__, i, group))) {
        if ("__data__" in node) subnode.__data__ = node.__data__;
        subgroup[i] = subnode;
      }
    }
  }

  return new Selection(subgroups, this._parents);
};

function empty() {
  return [];
}

var selectorAll = function(selector) {
  return selector == null ? empty : function() {
    return this.querySelectorAll(selector);
  };
};

var selection_selectAll = function(select) {
  if (typeof select !== "function") select = selectorAll(select);

  for (var groups = this._groups, m = groups.length, subgroups = [], parents = [], j = 0; j < m; ++j) {
    for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
      if (node = group[i]) {
        subgroups.push(select.call(node, node.__data__, i, group));
        parents.push(node);
      }
    }
  }

  return new Selection(subgroups, parents);
};

var selection_filter = function(match) {
  if (typeof match !== "function") match = matcher$1(match);

  for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
    for (var group = groups[j], n = group.length, subgroup = subgroups[j] = [], node, i = 0; i < n; ++i) {
      if ((node = group[i]) && match.call(node, node.__data__, i, group)) {
        subgroup.push(node);
      }
    }
  }

  return new Selection(subgroups, this._parents);
};

var sparse = function(update) {
  return new Array(update.length);
};

var selection_enter = function() {
  return new Selection(this._enter || this._groups.map(sparse), this._parents);
};

function EnterNode(parent, datum) {
  this.ownerDocument = parent.ownerDocument;
  this.namespaceURI = parent.namespaceURI;
  this._next = null;
  this._parent = parent;
  this.__data__ = datum;
}

EnterNode.prototype = {
  constructor: EnterNode,
  appendChild: function(child) { return this._parent.insertBefore(child, this._next); },
  insertBefore: function(child, next) { return this._parent.insertBefore(child, next); },
  querySelector: function(selector) { return this._parent.querySelector(selector); },
  querySelectorAll: function(selector) { return this._parent.querySelectorAll(selector); }
};

var constant = function(x) {
  return function() {
    return x;
  };
};

var keyPrefix = "$"; // Protect against keys like “__proto__”.

function bindIndex(parent, group, enter, update, exit, data) {
  var i = 0,
      node,
      groupLength = group.length,
      dataLength = data.length;

  // Put any non-null nodes that fit into update.
  // Put any null nodes into enter.
  // Put any remaining data into enter.
  for (; i < dataLength; ++i) {
    if (node = group[i]) {
      node.__data__ = data[i];
      update[i] = node;
    } else {
      enter[i] = new EnterNode(parent, data[i]);
    }
  }

  // Put any non-null nodes that don’t fit into exit.
  for (; i < groupLength; ++i) {
    if (node = group[i]) {
      exit[i] = node;
    }
  }
}

function bindKey(parent, group, enter, update, exit, data, key) {
  var i,
      node,
      nodeByKeyValue = {},
      groupLength = group.length,
      dataLength = data.length,
      keyValues = new Array(groupLength),
      keyValue;

  // Compute the key for each node.
  // If multiple nodes have the same key, the duplicates are added to exit.
  for (i = 0; i < groupLength; ++i) {
    if (node = group[i]) {
      keyValues[i] = keyValue = keyPrefix + key.call(node, node.__data__, i, group);
      if (keyValue in nodeByKeyValue) {
        exit[i] = node;
      } else {
        nodeByKeyValue[keyValue] = node;
      }
    }
  }

  // Compute the key for each datum.
  // If there a node associated with this key, join and add it to update.
  // If there is not (or the key is a duplicate), add it to enter.
  for (i = 0; i < dataLength; ++i) {
    keyValue = keyPrefix + key.call(parent, data[i], i, data);
    if (node = nodeByKeyValue[keyValue]) {
      update[i] = node;
      node.__data__ = data[i];
      nodeByKeyValue[keyValue] = null;
    } else {
      enter[i] = new EnterNode(parent, data[i]);
    }
  }

  // Add any remaining nodes that were not bound to data to exit.
  for (i = 0; i < groupLength; ++i) {
    if ((node = group[i]) && (nodeByKeyValue[keyValues[i]] === node)) {
      exit[i] = node;
    }
  }
}

var selection_data = function(value, key) {
  if (!value) {
    data = new Array(this.size()), j = -1;
    this.each(function(d) { data[++j] = d; });
    return data;
  }

  var bind = key ? bindKey : bindIndex,
      parents = this._parents,
      groups = this._groups;

  if (typeof value !== "function") value = constant(value);

  for (var m = groups.length, update = new Array(m), enter = new Array(m), exit = new Array(m), j = 0; j < m; ++j) {
    var parent = parents[j],
        group = groups[j],
        groupLength = group.length,
        data = value.call(parent, parent && parent.__data__, j, parents),
        dataLength = data.length,
        enterGroup = enter[j] = new Array(dataLength),
        updateGroup = update[j] = new Array(dataLength),
        exitGroup = exit[j] = new Array(groupLength);

    bind(parent, group, enterGroup, updateGroup, exitGroup, data, key);

    // Now connect the enter nodes to their following update node, such that
    // appendChild can insert the materialized enter node before this node,
    // rather than at the end of the parent node.
    for (var i0 = 0, i1 = 0, previous, next; i0 < dataLength; ++i0) {
      if (previous = enterGroup[i0]) {
        if (i0 >= i1) i1 = i0 + 1;
        while (!(next = updateGroup[i1]) && ++i1 < dataLength);
        previous._next = next || null;
      }
    }
  }

  update = new Selection(update, parents);
  update._enter = enter;
  update._exit = exit;
  return update;
};

var selection_exit = function() {
  return new Selection(this._exit || this._groups.map(sparse), this._parents);
};

var selection_merge = function(selection) {

  for (var groups0 = this._groups, groups1 = selection._groups, m0 = groups0.length, m1 = groups1.length, m = Math.min(m0, m1), merges = new Array(m0), j = 0; j < m; ++j) {
    for (var group0 = groups0[j], group1 = groups1[j], n = group0.length, merge = merges[j] = new Array(n), node, i = 0; i < n; ++i) {
      if (node = group0[i] || group1[i]) {
        merge[i] = node;
      }
    }
  }

  for (; j < m0; ++j) {
    merges[j] = groups0[j];
  }

  return new Selection(merges, this._parents);
};

var selection_order = function() {

  for (var groups = this._groups, j = -1, m = groups.length; ++j < m;) {
    for (var group = groups[j], i = group.length - 1, next = group[i], node; --i >= 0;) {
      if (node = group[i]) {
        if (next && next !== node.nextSibling) next.parentNode.insertBefore(node, next);
        next = node;
      }
    }
  }

  return this;
};

var selection_sort = function(compare) {
  if (!compare) compare = ascending;

  function compareNode(a, b) {
    return a && b ? compare(a.__data__, b.__data__) : !a - !b;
  }

  for (var groups = this._groups, m = groups.length, sortgroups = new Array(m), j = 0; j < m; ++j) {
    for (var group = groups[j], n = group.length, sortgroup = sortgroups[j] = new Array(n), node, i = 0; i < n; ++i) {
      if (node = group[i]) {
        sortgroup[i] = node;
      }
    }
    sortgroup.sort(compareNode);
  }

  return new Selection(sortgroups, this._parents).order();
};

function ascending(a, b) {
  return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN;
}

var selection_call = function() {
  var callback = arguments[0];
  arguments[0] = this;
  callback.apply(null, arguments);
  return this;
};

var selection_nodes = function() {
  var nodes = new Array(this.size()), i = -1;
  this.each(function() { nodes[++i] = this; });
  return nodes;
};

var selection_node = function() {

  for (var groups = this._groups, j = 0, m = groups.length; j < m; ++j) {
    for (var group = groups[j], i = 0, n = group.length; i < n; ++i) {
      var node = group[i];
      if (node) return node;
    }
  }

  return null;
};

var selection_size = function() {
  var size = 0;
  this.each(function() { ++size; });
  return size;
};

var selection_empty = function() {
  return !this.node();
};

var selection_each = function(callback) {

  for (var groups = this._groups, j = 0, m = groups.length; j < m; ++j) {
    for (var group = groups[j], i = 0, n = group.length, node; i < n; ++i) {
      if (node = group[i]) callback.call(node, node.__data__, i, group);
    }
  }

  return this;
};

function attrRemove(name) {
  return function() {
    this.removeAttribute(name);
  };
}

function attrRemoveNS(fullname) {
  return function() {
    this.removeAttributeNS(fullname.space, fullname.local);
  };
}

function attrConstant(name, value) {
  return function() {
    this.setAttribute(name, value);
  };
}

function attrConstantNS(fullname, value) {
  return function() {
    this.setAttributeNS(fullname.space, fullname.local, value);
  };
}

function attrFunction(name, value) {
  return function() {
    var v = value.apply(this, arguments);
    if (v == null) this.removeAttribute(name);
    else this.setAttribute(name, v);
  };
}

function attrFunctionNS(fullname, value) {
  return function() {
    var v = value.apply(this, arguments);
    if (v == null) this.removeAttributeNS(fullname.space, fullname.local);
    else this.setAttributeNS(fullname.space, fullname.local, v);
  };
}

var selection_attr = function(name, value) {
  var fullname = namespace(name);

  if (arguments.length < 2) {
    var node = this.node();
    return fullname.local
        ? node.getAttributeNS(fullname.space, fullname.local)
        : node.getAttribute(fullname);
  }

  return this.each((value == null
      ? (fullname.local ? attrRemoveNS : attrRemove) : (typeof value === "function"
      ? (fullname.local ? attrFunctionNS : attrFunction)
      : (fullname.local ? attrConstantNS : attrConstant)))(fullname, value));
};

var defaultView = function(node) {
  return (node.ownerDocument && node.ownerDocument.defaultView) // node is a Node
      || (node.document && node) // node is a Window
      || node.defaultView; // node is a Document
};

function styleRemove(name) {
  return function() {
    this.style.removeProperty(name);
  };
}

function styleConstant(name, value, priority) {
  return function() {
    this.style.setProperty(name, value, priority);
  };
}

function styleFunction(name, value, priority) {
  return function() {
    var v = value.apply(this, arguments);
    if (v == null) this.style.removeProperty(name);
    else this.style.setProperty(name, v, priority);
  };
}

var selection_style = function(name, value, priority) {
  return arguments.length > 1
      ? this.each((value == null
            ? styleRemove : typeof value === "function"
            ? styleFunction
            : styleConstant)(name, value, priority == null ? "" : priority))
      : styleValue(this.node(), name);
};

function styleValue(node, name) {
  return node.style.getPropertyValue(name)
      || defaultView(node).getComputedStyle(node, null).getPropertyValue(name);
}

function propertyRemove(name) {
  return function() {
    delete this[name];
  };
}

function propertyConstant(name, value) {
  return function() {
    this[name] = value;
  };
}

function propertyFunction(name, value) {
  return function() {
    var v = value.apply(this, arguments);
    if (v == null) delete this[name];
    else this[name] = v;
  };
}

var selection_property = function(name, value) {
  return arguments.length > 1
      ? this.each((value == null
          ? propertyRemove : typeof value === "function"
          ? propertyFunction
          : propertyConstant)(name, value))
      : this.node()[name];
};

function classArray(string) {
  return string.trim().split(/^|\s+/);
}

function classList(node) {
  return node.classList || new ClassList(node);
}

function ClassList(node) {
  this._node = node;
  this._names = classArray(node.getAttribute("class") || "");
}

ClassList.prototype = {
  add: function(name) {
    var i = this._names.indexOf(name);
    if (i < 0) {
      this._names.push(name);
      this._node.setAttribute("class", this._names.join(" "));
    }
  },
  remove: function(name) {
    var i = this._names.indexOf(name);
    if (i >= 0) {
      this._names.splice(i, 1);
      this._node.setAttribute("class", this._names.join(" "));
    }
  },
  contains: function(name) {
    return this._names.indexOf(name) >= 0;
  }
};

function classedAdd(node, names) {
  var list = classList(node), i = -1, n = names.length;
  while (++i < n) list.add(names[i]);
}

function classedRemove(node, names) {
  var list = classList(node), i = -1, n = names.length;
  while (++i < n) list.remove(names[i]);
}

function classedTrue(names) {
  return function() {
    classedAdd(this, names);
  };
}

function classedFalse(names) {
  return function() {
    classedRemove(this, names);
  };
}

function classedFunction(names, value) {
  return function() {
    (value.apply(this, arguments) ? classedAdd : classedRemove)(this, names);
  };
}

var selection_classed = function(name, value) {
  var names = classArray(name + "");

  if (arguments.length < 2) {
    var list = classList(this.node()), i = -1, n = names.length;
    while (++i < n) if (!list.contains(names[i])) return false;
    return true;
  }

  return this.each((typeof value === "function"
      ? classedFunction : value
      ? classedTrue
      : classedFalse)(names, value));
};

function textRemove() {
  this.textContent = "";
}

function textConstant(value) {
  return function() {
    this.textContent = value;
  };
}

function textFunction(value) {
  return function() {
    var v = value.apply(this, arguments);
    this.textContent = v == null ? "" : v;
  };
}

var selection_text = function(value) {
  return arguments.length
      ? this.each(value == null
          ? textRemove : (typeof value === "function"
          ? textFunction
          : textConstant)(value))
      : this.node().textContent;
};

function htmlRemove() {
  this.innerHTML = "";
}

function htmlConstant(value) {
  return function() {
    this.innerHTML = value;
  };
}

function htmlFunction(value) {
  return function() {
    var v = value.apply(this, arguments);
    this.innerHTML = v == null ? "" : v;
  };
}

var selection_html = function(value) {
  return arguments.length
      ? this.each(value == null
          ? htmlRemove : (typeof value === "function"
          ? htmlFunction
          : htmlConstant)(value))
      : this.node().innerHTML;
};

function raise() {
  if (this.nextSibling) this.parentNode.appendChild(this);
}

var selection_raise = function() {
  return this.each(raise);
};

function lower() {
  if (this.previousSibling) this.parentNode.insertBefore(this, this.parentNode.firstChild);
}

var selection_lower = function() {
  return this.each(lower);
};

var selection_append = function(name) {
  var create = typeof name === "function" ? name : creator(name);
  return this.select(function() {
    return this.appendChild(create.apply(this, arguments));
  });
};

function constantNull() {
  return null;
}

var selection_insert = function(name, before) {
  var create = typeof name === "function" ? name : creator(name),
      select = before == null ? constantNull : typeof before === "function" ? before : selector(before);
  return this.select(function() {
    return this.insertBefore(create.apply(this, arguments), select.apply(this, arguments) || null);
  });
};

function remove() {
  var parent = this.parentNode;
  if (parent) parent.removeChild(this);
}

var selection_remove = function() {
  return this.each(remove);
};

var selection_datum = function(value) {
  return arguments.length
      ? this.property("__data__", value)
      : this.node().__data__;
};

function dispatchEvent(node, type, params) {
  var window = defaultView(node),
      event = window.CustomEvent;

  if (typeof event === "function") {
    event = new event(type, params);
  } else {
    event = window.document.createEvent("Event");
    if (params) event.initEvent(type, params.bubbles, params.cancelable), event.detail = params.detail;
    else event.initEvent(type, false, false);
  }

  node.dispatchEvent(event);
}

function dispatchConstant(type, params) {
  return function() {
    return dispatchEvent(this, type, params);
  };
}

function dispatchFunction(type, params) {
  return function() {
    return dispatchEvent(this, type, params.apply(this, arguments));
  };
}

var selection_dispatch = function(type, params) {
  return this.each((typeof params === "function"
      ? dispatchFunction
      : dispatchConstant)(type, params));
};

var root = [null];

function Selection(groups, parents) {
  this._groups = groups;
  this._parents = parents;
}

function selection() {
  return new Selection([[document.documentElement]], root);
}

Selection.prototype = selection.prototype = {
  constructor: Selection,
  select: selection_select,
  selectAll: selection_selectAll,
  filter: selection_filter,
  data: selection_data,
  enter: selection_enter,
  exit: selection_exit,
  merge: selection_merge,
  order: selection_order,
  sort: selection_sort,
  call: selection_call,
  nodes: selection_nodes,
  node: selection_node,
  size: selection_size,
  empty: selection_empty,
  each: selection_each,
  attr: selection_attr,
  style: selection_style,
  property: selection_property,
  classed: selection_classed,
  text: selection_text,
  html: selection_html,
  raise: selection_raise,
  lower: selection_lower,
  append: selection_append,
  insert: selection_insert,
  remove: selection_remove,
  datum: selection_datum,
  on: selection_on,
  dispatch: selection_dispatch
};

var select = function(selector) {
  return typeof selector === "string"
      ? new Selection([[document.querySelector(selector)]], [document.documentElement])
      : new Selection([[selector]], root);
};

var selectAll = function(selector) {
  return typeof selector === "string"
      ? new Selection([document.querySelectorAll(selector)], [document.documentElement])
      : new Selection([selector == null ? [] : selector], root);
};

var touch = function(node, touches, identifier) {
  if (arguments.length < 3) identifier = touches, touches = sourceEvent().changedTouches;

  for (var i = 0, n = touches ? touches.length : 0, touch; i < n; ++i) {
    if ((touch = touches[i]).identifier === identifier) {
      return point(node, touch);
    }
  }

  return null;
};

var touches = function(node, touches) {
  if (touches == null) touches = sourceEvent().touches;

  for (var i = 0, n = touches ? touches.length : 0, points = new Array(n); i < n; ++i) {
    points[i] = point(node, touches[i]);
  }

  return points;
};

exports.creator = creator;
exports.local = local;
exports.matcher = matcher$1;
exports.mouse = mouse;
exports.namespace = namespace;
exports.namespaces = namespaces;
exports.select = select;
exports.selectAll = selectAll;
exports.selection = selection;
exports.selector = selector;
exports.selectorAll = selectorAll;
exports.style = styleValue;
exports.touch = touch;
exports.touches = touches;
exports.window = defaultView;
exports.customEvent = customEvent;

Object.defineProperty(exports, '__esModule', { value: true });

})));

},{}],4:[function(require,module,exports){
// https://d3js.org/d3-shape/ Version 1.2.0. Copyright 2017 Mike Bostock.
(function (global, factory) {
	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('d3-path')) :
	typeof define === 'function' && define.amd ? define(['exports', 'd3-path'], factory) :
	(factory((global.d3 = global.d3 || {}),global.d3));
}(this, (function (exports,d3Path) { 'use strict';

var constant = function(x) {
  return function constant() {
    return x;
  };
};

var abs = Math.abs;
var atan2 = Math.atan2;
var cos = Math.cos;
var max = Math.max;
var min = Math.min;
var sin = Math.sin;
var sqrt = Math.sqrt;

var epsilon = 1e-12;
var pi = Math.PI;
var halfPi = pi / 2;
var tau = 2 * pi;

function acos(x) {
  return x > 1 ? 0 : x < -1 ? pi : Math.acos(x);
}

function asin(x) {
  return x >= 1 ? halfPi : x <= -1 ? -halfPi : Math.asin(x);
}

function arcInnerRadius(d) {
  return d.innerRadius;
}

function arcOuterRadius(d) {
  return d.outerRadius;
}

function arcStartAngle(d) {
  return d.startAngle;
}

function arcEndAngle(d) {
  return d.endAngle;
}

function arcPadAngle(d) {
  return d && d.padAngle; // Note: optional!
}

function intersect(x0, y0, x1, y1, x2, y2, x3, y3) {
  var x10 = x1 - x0, y10 = y1 - y0,
      x32 = x3 - x2, y32 = y3 - y2,
      t = (x32 * (y0 - y2) - y32 * (x0 - x2)) / (y32 * x10 - x32 * y10);
  return [x0 + t * x10, y0 + t * y10];
}

// Compute perpendicular offset line of length rc.
// http://mathworld.wolfram.com/Circle-LineIntersection.html
function cornerTangents(x0, y0, x1, y1, r1, rc, cw) {
  var x01 = x0 - x1,
      y01 = y0 - y1,
      lo = (cw ? rc : -rc) / sqrt(x01 * x01 + y01 * y01),
      ox = lo * y01,
      oy = -lo * x01,
      x11 = x0 + ox,
      y11 = y0 + oy,
      x10 = x1 + ox,
      y10 = y1 + oy,
      x00 = (x11 + x10) / 2,
      y00 = (y11 + y10) / 2,
      dx = x10 - x11,
      dy = y10 - y11,
      d2 = dx * dx + dy * dy,
      r = r1 - rc,
      D = x11 * y10 - x10 * y11,
      d = (dy < 0 ? -1 : 1) * sqrt(max(0, r * r * d2 - D * D)),
      cx0 = (D * dy - dx * d) / d2,
      cy0 = (-D * dx - dy * d) / d2,
      cx1 = (D * dy + dx * d) / d2,
      cy1 = (-D * dx + dy * d) / d2,
      dx0 = cx0 - x00,
      dy0 = cy0 - y00,
      dx1 = cx1 - x00,
      dy1 = cy1 - y00;

  // Pick the closer of the two intersection points.
  // TODO Is there a faster way to determine which intersection to use?
  if (dx0 * dx0 + dy0 * dy0 > dx1 * dx1 + dy1 * dy1) cx0 = cx1, cy0 = cy1;

  return {
    cx: cx0,
    cy: cy0,
    x01: -ox,
    y01: -oy,
    x11: cx0 * (r1 / r - 1),
    y11: cy0 * (r1 / r - 1)
  };
}

var arc = function() {
  var innerRadius = arcInnerRadius,
      outerRadius = arcOuterRadius,
      cornerRadius = constant(0),
      padRadius = null,
      startAngle = arcStartAngle,
      endAngle = arcEndAngle,
      padAngle = arcPadAngle,
      context = null;

  function arc() {
    var buffer,
        r,
        r0 = +innerRadius.apply(this, arguments),
        r1 = +outerRadius.apply(this, arguments),
        a0 = startAngle.apply(this, arguments) - halfPi,
        a1 = endAngle.apply(this, arguments) - halfPi,
        da = abs(a1 - a0),
        cw = a1 > a0;

    if (!context) context = buffer = d3Path.path();

    // Ensure that the outer radius is always larger than the inner radius.
    if (r1 < r0) r = r1, r1 = r0, r0 = r;

    // Is it a point?
    if (!(r1 > epsilon)) context.moveTo(0, 0);

    // Or is it a circle or annulus?
    else if (da > tau - epsilon) {
      context.moveTo(r1 * cos(a0), r1 * sin(a0));
      context.arc(0, 0, r1, a0, a1, !cw);
      if (r0 > epsilon) {
        context.moveTo(r0 * cos(a1), r0 * sin(a1));
        context.arc(0, 0, r0, a1, a0, cw);
      }
    }

    // Or is it a circular or annular sector?
    else {
      var a01 = a0,
          a11 = a1,
          a00 = a0,
          a10 = a1,
          da0 = da,
          da1 = da,
          ap = padAngle.apply(this, arguments) / 2,
          rp = (ap > epsilon) && (padRadius ? +padRadius.apply(this, arguments) : sqrt(r0 * r0 + r1 * r1)),
          rc = min(abs(r1 - r0) / 2, +cornerRadius.apply(this, arguments)),
          rc0 = rc,
          rc1 = rc,
          t0,
          t1;

      // Apply padding? Note that since r1 ≥ r0, da1 ≥ da0.
      if (rp > epsilon) {
        var p0 = asin(rp / r0 * sin(ap)),
            p1 = asin(rp / r1 * sin(ap));
        if ((da0 -= p0 * 2) > epsilon) p0 *= (cw ? 1 : -1), a00 += p0, a10 -= p0;
        else da0 = 0, a00 = a10 = (a0 + a1) / 2;
        if ((da1 -= p1 * 2) > epsilon) p1 *= (cw ? 1 : -1), a01 += p1, a11 -= p1;
        else da1 = 0, a01 = a11 = (a0 + a1) / 2;
      }

      var x01 = r1 * cos(a01),
          y01 = r1 * sin(a01),
          x10 = r0 * cos(a10),
          y10 = r0 * sin(a10);

      // Apply rounded corners?
      if (rc > epsilon) {
        var x11 = r1 * cos(a11),
            y11 = r1 * sin(a11),
            x00 = r0 * cos(a00),
            y00 = r0 * sin(a00);

        // Restrict the corner radius according to the sector angle.
        if (da < pi) {
          var oc = da0 > epsilon ? intersect(x01, y01, x00, y00, x11, y11, x10, y10) : [x10, y10],
              ax = x01 - oc[0],
              ay = y01 - oc[1],
              bx = x11 - oc[0],
              by = y11 - oc[1],
              kc = 1 / sin(acos((ax * bx + ay * by) / (sqrt(ax * ax + ay * ay) * sqrt(bx * bx + by * by))) / 2),
              lc = sqrt(oc[0] * oc[0] + oc[1] * oc[1]);
          rc0 = min(rc, (r0 - lc) / (kc - 1));
          rc1 = min(rc, (r1 - lc) / (kc + 1));
        }
      }

      // Is the sector collapsed to a line?
      if (!(da1 > epsilon)) context.moveTo(x01, y01);

      // Does the sector’s outer ring have rounded corners?
      else if (rc1 > epsilon) {
        t0 = cornerTangents(x00, y00, x01, y01, r1, rc1, cw);
        t1 = cornerTangents(x11, y11, x10, y10, r1, rc1, cw);

        context.moveTo(t0.cx + t0.x01, t0.cy + t0.y01);

        // Have the corners merged?
        if (rc1 < rc) context.arc(t0.cx, t0.cy, rc1, atan2(t0.y01, t0.x01), atan2(t1.y01, t1.x01), !cw);

        // Otherwise, draw the two corners and the ring.
        else {
          context.arc(t0.cx, t0.cy, rc1, atan2(t0.y01, t0.x01), atan2(t0.y11, t0.x11), !cw);
          context.arc(0, 0, r1, atan2(t0.cy + t0.y11, t0.cx + t0.x11), atan2(t1.cy + t1.y11, t1.cx + t1.x11), !cw);
          context.arc(t1.cx, t1.cy, rc1, atan2(t1.y11, t1.x11), atan2(t1.y01, t1.x01), !cw);
        }
      }

      // Or is the outer ring just a circular arc?
      else context.moveTo(x01, y01), context.arc(0, 0, r1, a01, a11, !cw);

      // Is there no inner ring, and it’s a circular sector?
      // Or perhaps it’s an annular sector collapsed due to padding?
      if (!(r0 > epsilon) || !(da0 > epsilon)) context.lineTo(x10, y10);

      // Does the sector’s inner ring (or point) have rounded corners?
      else if (rc0 > epsilon) {
        t0 = cornerTangents(x10, y10, x11, y11, r0, -rc0, cw);
        t1 = cornerTangents(x01, y01, x00, y00, r0, -rc0, cw);

        context.lineTo(t0.cx + t0.x01, t0.cy + t0.y01);

        // Have the corners merged?
        if (rc0 < rc) context.arc(t0.cx, t0.cy, rc0, atan2(t0.y01, t0.x01), atan2(t1.y01, t1.x01), !cw);

        // Otherwise, draw the two corners and the ring.
        else {
          context.arc(t0.cx, t0.cy, rc0, atan2(t0.y01, t0.x01), atan2(t0.y11, t0.x11), !cw);
          context.arc(0, 0, r0, atan2(t0.cy + t0.y11, t0.cx + t0.x11), atan2(t1.cy + t1.y11, t1.cx + t1.x11), cw);
          context.arc(t1.cx, t1.cy, rc0, atan2(t1.y11, t1.x11), atan2(t1.y01, t1.x01), !cw);
        }
      }

      // Or is the inner ring just a circular arc?
      else context.arc(0, 0, r0, a10, a00, cw);
    }

    context.closePath();

    if (buffer) return context = null, buffer + "" || null;
  }

  arc.centroid = function() {
    var r = (+innerRadius.apply(this, arguments) + +outerRadius.apply(this, arguments)) / 2,
        a = (+startAngle.apply(this, arguments) + +endAngle.apply(this, arguments)) / 2 - pi / 2;
    return [cos(a) * r, sin(a) * r];
  };

  arc.innerRadius = function(_) {
    return arguments.length ? (innerRadius = typeof _ === "function" ? _ : constant(+_), arc) : innerRadius;
  };

  arc.outerRadius = function(_) {
    return arguments.length ? (outerRadius = typeof _ === "function" ? _ : constant(+_), arc) : outerRadius;
  };

  arc.cornerRadius = function(_) {
    return arguments.length ? (cornerRadius = typeof _ === "function" ? _ : constant(+_), arc) : cornerRadius;
  };

  arc.padRadius = function(_) {
    return arguments.length ? (padRadius = _ == null ? null : typeof _ === "function" ? _ : constant(+_), arc) : padRadius;
  };

  arc.startAngle = function(_) {
    return arguments.length ? (startAngle = typeof _ === "function" ? _ : constant(+_), arc) : startAngle;
  };

  arc.endAngle = function(_) {
    return arguments.length ? (endAngle = typeof _ === "function" ? _ : constant(+_), arc) : endAngle;
  };

  arc.padAngle = function(_) {
    return arguments.length ? (padAngle = typeof _ === "function" ? _ : constant(+_), arc) : padAngle;
  };

  arc.context = function(_) {
    return arguments.length ? ((context = _ == null ? null : _), arc) : context;
  };

  return arc;
};

function Linear(context) {
  this._context = context;
}

Linear.prototype = {
  areaStart: function() {
    this._line = 0;
  },
  areaEnd: function() {
    this._line = NaN;
  },
  lineStart: function() {
    this._point = 0;
  },
  lineEnd: function() {
    if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
    this._line = 1 - this._line;
  },
  point: function(x, y) {
    x = +x, y = +y;
    switch (this._point) {
      case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
      case 1: this._point = 2; // proceed
      default: this._context.lineTo(x, y); break;
    }
  }
};

var curveLinear = function(context) {
  return new Linear(context);
};

function x(p) {
  return p[0];
}

function y(p) {
  return p[1];
}

var line = function() {
  var x$$1 = x,
      y$$1 = y,
      defined = constant(true),
      context = null,
      curve = curveLinear,
      output = null;

  function line(data) {
    var i,
        n = data.length,
        d,
        defined0 = false,
        buffer;

    if (context == null) output = curve(buffer = d3Path.path());

    for (i = 0; i <= n; ++i) {
      if (!(i < n && defined(d = data[i], i, data)) === defined0) {
        if (defined0 = !defined0) output.lineStart();
        else output.lineEnd();
      }
      if (defined0) output.point(+x$$1(d, i, data), +y$$1(d, i, data));
    }

    if (buffer) return output = null, buffer + "" || null;
  }

  line.x = function(_) {
    return arguments.length ? (x$$1 = typeof _ === "function" ? _ : constant(+_), line) : x$$1;
  };

  line.y = function(_) {
    return arguments.length ? (y$$1 = typeof _ === "function" ? _ : constant(+_), line) : y$$1;
  };

  line.defined = function(_) {
    return arguments.length ? (defined = typeof _ === "function" ? _ : constant(!!_), line) : defined;
  };

  line.curve = function(_) {
    return arguments.length ? (curve = _, context != null && (output = curve(context)), line) : curve;
  };

  line.context = function(_) {
    return arguments.length ? (_ == null ? context = output = null : output = curve(context = _), line) : context;
  };

  return line;
};

var area = function() {
  var x0 = x,
      x1 = null,
      y0 = constant(0),
      y1 = y,
      defined = constant(true),
      context = null,
      curve = curveLinear,
      output = null;

  function area(data) {
    var i,
        j,
        k,
        n = data.length,
        d,
        defined0 = false,
        buffer,
        x0z = new Array(n),
        y0z = new Array(n);

    if (context == null) output = curve(buffer = d3Path.path());

    for (i = 0; i <= n; ++i) {
      if (!(i < n && defined(d = data[i], i, data)) === defined0) {
        if (defined0 = !defined0) {
          j = i;
          output.areaStart();
          output.lineStart();
        } else {
          output.lineEnd();
          output.lineStart();
          for (k = i - 1; k >= j; --k) {
            output.point(x0z[k], y0z[k]);
          }
          output.lineEnd();
          output.areaEnd();
        }
      }
      if (defined0) {
        x0z[i] = +x0(d, i, data), y0z[i] = +y0(d, i, data);
        output.point(x1 ? +x1(d, i, data) : x0z[i], y1 ? +y1(d, i, data) : y0z[i]);
      }
    }

    if (buffer) return output = null, buffer + "" || null;
  }

  function arealine() {
    return line().defined(defined).curve(curve).context(context);
  }

  area.x = function(_) {
    return arguments.length ? (x0 = typeof _ === "function" ? _ : constant(+_), x1 = null, area) : x0;
  };

  area.x0 = function(_) {
    return arguments.length ? (x0 = typeof _ === "function" ? _ : constant(+_), area) : x0;
  };

  area.x1 = function(_) {
    return arguments.length ? (x1 = _ == null ? null : typeof _ === "function" ? _ : constant(+_), area) : x1;
  };

  area.y = function(_) {
    return arguments.length ? (y0 = typeof _ === "function" ? _ : constant(+_), y1 = null, area) : y0;
  };

  area.y0 = function(_) {
    return arguments.length ? (y0 = typeof _ === "function" ? _ : constant(+_), area) : y0;
  };

  area.y1 = function(_) {
    return arguments.length ? (y1 = _ == null ? null : typeof _ === "function" ? _ : constant(+_), area) : y1;
  };

  area.lineX0 =
  area.lineY0 = function() {
    return arealine().x(x0).y(y0);
  };

  area.lineY1 = function() {
    return arealine().x(x0).y(y1);
  };

  area.lineX1 = function() {
    return arealine().x(x1).y(y0);
  };

  area.defined = function(_) {
    return arguments.length ? (defined = typeof _ === "function" ? _ : constant(!!_), area) : defined;
  };

  area.curve = function(_) {
    return arguments.length ? (curve = _, context != null && (output = curve(context)), area) : curve;
  };

  area.context = function(_) {
    return arguments.length ? (_ == null ? context = output = null : output = curve(context = _), area) : context;
  };

  return area;
};

var descending = function(a, b) {
  return b < a ? -1 : b > a ? 1 : b >= a ? 0 : NaN;
};

var identity = function(d) {
  return d;
};

var pie = function() {
  var value = identity,
      sortValues = descending,
      sort = null,
      startAngle = constant(0),
      endAngle = constant(tau),
      padAngle = constant(0);

  function pie(data) {
    var i,
        n = data.length,
        j,
        k,
        sum = 0,
        index = new Array(n),
        arcs = new Array(n),
        a0 = +startAngle.apply(this, arguments),
        da = Math.min(tau, Math.max(-tau, endAngle.apply(this, arguments) - a0)),
        a1,
        p = Math.min(Math.abs(da) / n, padAngle.apply(this, arguments)),
        pa = p * (da < 0 ? -1 : 1),
        v;

    for (i = 0; i < n; ++i) {
      if ((v = arcs[index[i] = i] = +value(data[i], i, data)) > 0) {
        sum += v;
      }
    }

    // Optionally sort the arcs by previously-computed values or by data.
    if (sortValues != null) index.sort(function(i, j) { return sortValues(arcs[i], arcs[j]); });
    else if (sort != null) index.sort(function(i, j) { return sort(data[i], data[j]); });

    // Compute the arcs! They are stored in the original data's order.
    for (i = 0, k = sum ? (da - n * pa) / sum : 0; i < n; ++i, a0 = a1) {
      j = index[i], v = arcs[j], a1 = a0 + (v > 0 ? v * k : 0) + pa, arcs[j] = {
        data: data[j],
        index: i,
        value: v,
        startAngle: a0,
        endAngle: a1,
        padAngle: p
      };
    }

    return arcs;
  }

  pie.value = function(_) {
    return arguments.length ? (value = typeof _ === "function" ? _ : constant(+_), pie) : value;
  };

  pie.sortValues = function(_) {
    return arguments.length ? (sortValues = _, sort = null, pie) : sortValues;
  };

  pie.sort = function(_) {
    return arguments.length ? (sort = _, sortValues = null, pie) : sort;
  };

  pie.startAngle = function(_) {
    return arguments.length ? (startAngle = typeof _ === "function" ? _ : constant(+_), pie) : startAngle;
  };

  pie.endAngle = function(_) {
    return arguments.length ? (endAngle = typeof _ === "function" ? _ : constant(+_), pie) : endAngle;
  };

  pie.padAngle = function(_) {
    return arguments.length ? (padAngle = typeof _ === "function" ? _ : constant(+_), pie) : padAngle;
  };

  return pie;
};

var curveRadialLinear = curveRadial(curveLinear);

function Radial(curve) {
  this._curve = curve;
}

Radial.prototype = {
  areaStart: function() {
    this._curve.areaStart();
  },
  areaEnd: function() {
    this._curve.areaEnd();
  },
  lineStart: function() {
    this._curve.lineStart();
  },
  lineEnd: function() {
    this._curve.lineEnd();
  },
  point: function(a, r) {
    this._curve.point(r * Math.sin(a), r * -Math.cos(a));
  }
};

function curveRadial(curve) {

  function radial(context) {
    return new Radial(curve(context));
  }

  radial._curve = curve;

  return radial;
}

function lineRadial(l) {
  var c = l.curve;

  l.angle = l.x, delete l.x;
  l.radius = l.y, delete l.y;

  l.curve = function(_) {
    return arguments.length ? c(curveRadial(_)) : c()._curve;
  };

  return l;
}

var lineRadial$1 = function() {
  return lineRadial(line().curve(curveRadialLinear));
};

var areaRadial = function() {
  var a = area().curve(curveRadialLinear),
      c = a.curve,
      x0 = a.lineX0,
      x1 = a.lineX1,
      y0 = a.lineY0,
      y1 = a.lineY1;

  a.angle = a.x, delete a.x;
  a.startAngle = a.x0, delete a.x0;
  a.endAngle = a.x1, delete a.x1;
  a.radius = a.y, delete a.y;
  a.innerRadius = a.y0, delete a.y0;
  a.outerRadius = a.y1, delete a.y1;
  a.lineStartAngle = function() { return lineRadial(x0()); }, delete a.lineX0;
  a.lineEndAngle = function() { return lineRadial(x1()); }, delete a.lineX1;
  a.lineInnerRadius = function() { return lineRadial(y0()); }, delete a.lineY0;
  a.lineOuterRadius = function() { return lineRadial(y1()); }, delete a.lineY1;

  a.curve = function(_) {
    return arguments.length ? c(curveRadial(_)) : c()._curve;
  };

  return a;
};

var pointRadial = function(x, y) {
  return [(y = +y) * Math.cos(x -= Math.PI / 2), y * Math.sin(x)];
};

var slice = Array.prototype.slice;

function linkSource(d) {
  return d.source;
}

function linkTarget(d) {
  return d.target;
}

function link(curve) {
  var source = linkSource,
      target = linkTarget,
      x$$1 = x,
      y$$1 = y,
      context = null;

  function link() {
    var buffer, argv = slice.call(arguments), s = source.apply(this, argv), t = target.apply(this, argv);
    if (!context) context = buffer = d3Path.path();
    curve(context, +x$$1.apply(this, (argv[0] = s, argv)), +y$$1.apply(this, argv), +x$$1.apply(this, (argv[0] = t, argv)), +y$$1.apply(this, argv));
    if (buffer) return context = null, buffer + "" || null;
  }

  link.source = function(_) {
    return arguments.length ? (source = _, link) : source;
  };

  link.target = function(_) {
    return arguments.length ? (target = _, link) : target;
  };

  link.x = function(_) {
    return arguments.length ? (x$$1 = typeof _ === "function" ? _ : constant(+_), link) : x$$1;
  };

  link.y = function(_) {
    return arguments.length ? (y$$1 = typeof _ === "function" ? _ : constant(+_), link) : y$$1;
  };

  link.context = function(_) {
    return arguments.length ? ((context = _ == null ? null : _), link) : context;
  };

  return link;
}

function curveHorizontal(context, x0, y0, x1, y1) {
  context.moveTo(x0, y0);
  context.bezierCurveTo(x0 = (x0 + x1) / 2, y0, x0, y1, x1, y1);
}

function curveVertical(context, x0, y0, x1, y1) {
  context.moveTo(x0, y0);
  context.bezierCurveTo(x0, y0 = (y0 + y1) / 2, x1, y0, x1, y1);
}

function curveRadial$1(context, x0, y0, x1, y1) {
  var p0 = pointRadial(x0, y0),
      p1 = pointRadial(x0, y0 = (y0 + y1) / 2),
      p2 = pointRadial(x1, y0),
      p3 = pointRadial(x1, y1);
  context.moveTo(p0[0], p0[1]);
  context.bezierCurveTo(p1[0], p1[1], p2[0], p2[1], p3[0], p3[1]);
}

function linkHorizontal() {
  return link(curveHorizontal);
}

function linkVertical() {
  return link(curveVertical);
}

function linkRadial() {
  var l = link(curveRadial$1);
  l.angle = l.x, delete l.x;
  l.radius = l.y, delete l.y;
  return l;
}

var circle = {
  draw: function(context, size) {
    var r = Math.sqrt(size / pi);
    context.moveTo(r, 0);
    context.arc(0, 0, r, 0, tau);
  }
};

var cross = {
  draw: function(context, size) {
    var r = Math.sqrt(size / 5) / 2;
    context.moveTo(-3 * r, -r);
    context.lineTo(-r, -r);
    context.lineTo(-r, -3 * r);
    context.lineTo(r, -3 * r);
    context.lineTo(r, -r);
    context.lineTo(3 * r, -r);
    context.lineTo(3 * r, r);
    context.lineTo(r, r);
    context.lineTo(r, 3 * r);
    context.lineTo(-r, 3 * r);
    context.lineTo(-r, r);
    context.lineTo(-3 * r, r);
    context.closePath();
  }
};

var tan30 = Math.sqrt(1 / 3);
var tan30_2 = tan30 * 2;

var diamond = {
  draw: function(context, size) {
    var y = Math.sqrt(size / tan30_2),
        x = y * tan30;
    context.moveTo(0, -y);
    context.lineTo(x, 0);
    context.lineTo(0, y);
    context.lineTo(-x, 0);
    context.closePath();
  }
};

var ka = 0.89081309152928522810;
var kr = Math.sin(pi / 10) / Math.sin(7 * pi / 10);
var kx = Math.sin(tau / 10) * kr;
var ky = -Math.cos(tau / 10) * kr;

var star = {
  draw: function(context, size) {
    var r = Math.sqrt(size * ka),
        x = kx * r,
        y = ky * r;
    context.moveTo(0, -r);
    context.lineTo(x, y);
    for (var i = 1; i < 5; ++i) {
      var a = tau * i / 5,
          c = Math.cos(a),
          s = Math.sin(a);
      context.lineTo(s * r, -c * r);
      context.lineTo(c * x - s * y, s * x + c * y);
    }
    context.closePath();
  }
};

var square = {
  draw: function(context, size) {
    var w = Math.sqrt(size),
        x = -w / 2;
    context.rect(x, x, w, w);
  }
};

var sqrt3 = Math.sqrt(3);

var triangle = {
  draw: function(context, size) {
    var y = -Math.sqrt(size / (sqrt3 * 3));
    context.moveTo(0, y * 2);
    context.lineTo(-sqrt3 * y, -y);
    context.lineTo(sqrt3 * y, -y);
    context.closePath();
  }
};

var c = -0.5;
var s = Math.sqrt(3) / 2;
var k = 1 / Math.sqrt(12);
var a = (k / 2 + 1) * 3;

var wye = {
  draw: function(context, size) {
    var r = Math.sqrt(size / a),
        x0 = r / 2,
        y0 = r * k,
        x1 = x0,
        y1 = r * k + r,
        x2 = -x1,
        y2 = y1;
    context.moveTo(x0, y0);
    context.lineTo(x1, y1);
    context.lineTo(x2, y2);
    context.lineTo(c * x0 - s * y0, s * x0 + c * y0);
    context.lineTo(c * x1 - s * y1, s * x1 + c * y1);
    context.lineTo(c * x2 - s * y2, s * x2 + c * y2);
    context.lineTo(c * x0 + s * y0, c * y0 - s * x0);
    context.lineTo(c * x1 + s * y1, c * y1 - s * x1);
    context.lineTo(c * x2 + s * y2, c * y2 - s * x2);
    context.closePath();
  }
};

var symbols = [
  circle,
  cross,
  diamond,
  square,
  star,
  triangle,
  wye
];

var symbol = function() {
  var type = constant(circle),
      size = constant(64),
      context = null;

  function symbol() {
    var buffer;
    if (!context) context = buffer = d3Path.path();
    type.apply(this, arguments).draw(context, +size.apply(this, arguments));
    if (buffer) return context = null, buffer + "" || null;
  }

  symbol.type = function(_) {
    return arguments.length ? (type = typeof _ === "function" ? _ : constant(_), symbol) : type;
  };

  symbol.size = function(_) {
    return arguments.length ? (size = typeof _ === "function" ? _ : constant(+_), symbol) : size;
  };

  symbol.context = function(_) {
    return arguments.length ? (context = _ == null ? null : _, symbol) : context;
  };

  return symbol;
};

var noop = function() {};

function point(that, x, y) {
  that._context.bezierCurveTo(
    (2 * that._x0 + that._x1) / 3,
    (2 * that._y0 + that._y1) / 3,
    (that._x0 + 2 * that._x1) / 3,
    (that._y0 + 2 * that._y1) / 3,
    (that._x0 + 4 * that._x1 + x) / 6,
    (that._y0 + 4 * that._y1 + y) / 6
  );
}

function Basis(context) {
  this._context = context;
}

Basis.prototype = {
  areaStart: function() {
    this._line = 0;
  },
  areaEnd: function() {
    this._line = NaN;
  },
  lineStart: function() {
    this._x0 = this._x1 =
    this._y0 = this._y1 = NaN;
    this._point = 0;
  },
  lineEnd: function() {
    switch (this._point) {
      case 3: point(this, this._x1, this._y1); // proceed
      case 2: this._context.lineTo(this._x1, this._y1); break;
    }
    if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
    this._line = 1 - this._line;
  },
  point: function(x, y) {
    x = +x, y = +y;
    switch (this._point) {
      case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
      case 1: this._point = 2; break;
      case 2: this._point = 3; this._context.lineTo((5 * this._x0 + this._x1) / 6, (5 * this._y0 + this._y1) / 6); // proceed
      default: point(this, x, y); break;
    }
    this._x0 = this._x1, this._x1 = x;
    this._y0 = this._y1, this._y1 = y;
  }
};

var basis = function(context) {
  return new Basis(context);
};

function BasisClosed(context) {
  this._context = context;
}

BasisClosed.prototype = {
  areaStart: noop,
  areaEnd: noop,
  lineStart: function() {
    this._x0 = this._x1 = this._x2 = this._x3 = this._x4 =
    this._y0 = this._y1 = this._y2 = this._y3 = this._y4 = NaN;
    this._point = 0;
  },
  lineEnd: function() {
    switch (this._point) {
      case 1: {
        this._context.moveTo(this._x2, this._y2);
        this._context.closePath();
        break;
      }
      case 2: {
        this._context.moveTo((this._x2 + 2 * this._x3) / 3, (this._y2 + 2 * this._y3) / 3);
        this._context.lineTo((this._x3 + 2 * this._x2) / 3, (this._y3 + 2 * this._y2) / 3);
        this._context.closePath();
        break;
      }
      case 3: {
        this.point(this._x2, this._y2);
        this.point(this._x3, this._y3);
        this.point(this._x4, this._y4);
        break;
      }
    }
  },
  point: function(x, y) {
    x = +x, y = +y;
    switch (this._point) {
      case 0: this._point = 1; this._x2 = x, this._y2 = y; break;
      case 1: this._point = 2; this._x3 = x, this._y3 = y; break;
      case 2: this._point = 3; this._x4 = x, this._y4 = y; this._context.moveTo((this._x0 + 4 * this._x1 + x) / 6, (this._y0 + 4 * this._y1 + y) / 6); break;
      default: point(this, x, y); break;
    }
    this._x0 = this._x1, this._x1 = x;
    this._y0 = this._y1, this._y1 = y;
  }
};

var basisClosed = function(context) {
  return new BasisClosed(context);
};

function BasisOpen(context) {
  this._context = context;
}

BasisOpen.prototype = {
  areaStart: function() {
    this._line = 0;
  },
  areaEnd: function() {
    this._line = NaN;
  },
  lineStart: function() {
    this._x0 = this._x1 =
    this._y0 = this._y1 = NaN;
    this._point = 0;
  },
  lineEnd: function() {
    if (this._line || (this._line !== 0 && this._point === 3)) this._context.closePath();
    this._line = 1 - this._line;
  },
  point: function(x, y) {
    x = +x, y = +y;
    switch (this._point) {
      case 0: this._point = 1; break;
      case 1: this._point = 2; break;
      case 2: this._point = 3; var x0 = (this._x0 + 4 * this._x1 + x) / 6, y0 = (this._y0 + 4 * this._y1 + y) / 6; this._line ? this._context.lineTo(x0, y0) : this._context.moveTo(x0, y0); break;
      case 3: this._point = 4; // proceed
      default: point(this, x, y); break;
    }
    this._x0 = this._x1, this._x1 = x;
    this._y0 = this._y1, this._y1 = y;
  }
};

var basisOpen = function(context) {
  return new BasisOpen(context);
};

function Bundle(context, beta) {
  this._basis = new Basis(context);
  this._beta = beta;
}

Bundle.prototype = {
  lineStart: function() {
    this._x = [];
    this._y = [];
    this._basis.lineStart();
  },
  lineEnd: function() {
    var x = this._x,
        y = this._y,
        j = x.length - 1;

    if (j > 0) {
      var x0 = x[0],
          y0 = y[0],
          dx = x[j] - x0,
          dy = y[j] - y0,
          i = -1,
          t;

      while (++i <= j) {
        t = i / j;
        this._basis.point(
          this._beta * x[i] + (1 - this._beta) * (x0 + t * dx),
          this._beta * y[i] + (1 - this._beta) * (y0 + t * dy)
        );
      }
    }

    this._x = this._y = null;
    this._basis.lineEnd();
  },
  point: function(x, y) {
    this._x.push(+x);
    this._y.push(+y);
  }
};

var bundle = ((function custom(beta) {

  function bundle(context) {
    return beta === 1 ? new Basis(context) : new Bundle(context, beta);
  }

  bundle.beta = function(beta) {
    return custom(+beta);
  };

  return bundle;
}))(0.85);

function point$1(that, x, y) {
  that._context.bezierCurveTo(
    that._x1 + that._k * (that._x2 - that._x0),
    that._y1 + that._k * (that._y2 - that._y0),
    that._x2 + that._k * (that._x1 - x),
    that._y2 + that._k * (that._y1 - y),
    that._x2,
    that._y2
  );
}

function Cardinal(context, tension) {
  this._context = context;
  this._k = (1 - tension) / 6;
}

Cardinal.prototype = {
  areaStart: function() {
    this._line = 0;
  },
  areaEnd: function() {
    this._line = NaN;
  },
  lineStart: function() {
    this._x0 = this._x1 = this._x2 =
    this._y0 = this._y1 = this._y2 = NaN;
    this._point = 0;
  },
  lineEnd: function() {
    switch (this._point) {
      case 2: this._context.lineTo(this._x2, this._y2); break;
      case 3: point$1(this, this._x1, this._y1); break;
    }
    if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
    this._line = 1 - this._line;
  },
  point: function(x, y) {
    x = +x, y = +y;
    switch (this._point) {
      case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
      case 1: this._point = 2; this._x1 = x, this._y1 = y; break;
      case 2: this._point = 3; // proceed
      default: point$1(this, x, y); break;
    }
    this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
    this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
  }
};

var cardinal = ((function custom(tension) {

  function cardinal(context) {
    return new Cardinal(context, tension);
  }

  cardinal.tension = function(tension) {
    return custom(+tension);
  };

  return cardinal;
}))(0);

function CardinalClosed(context, tension) {
  this._context = context;
  this._k = (1 - tension) / 6;
}

CardinalClosed.prototype = {
  areaStart: noop,
  areaEnd: noop,
  lineStart: function() {
    this._x0 = this._x1 = this._x2 = this._x3 = this._x4 = this._x5 =
    this._y0 = this._y1 = this._y2 = this._y3 = this._y4 = this._y5 = NaN;
    this._point = 0;
  },
  lineEnd: function() {
    switch (this._point) {
      case 1: {
        this._context.moveTo(this._x3, this._y3);
        this._context.closePath();
        break;
      }
      case 2: {
        this._context.lineTo(this._x3, this._y3);
        this._context.closePath();
        break;
      }
      case 3: {
        this.point(this._x3, this._y3);
        this.point(this._x4, this._y4);
        this.point(this._x5, this._y5);
        break;
      }
    }
  },
  point: function(x, y) {
    x = +x, y = +y;
    switch (this._point) {
      case 0: this._point = 1; this._x3 = x, this._y3 = y; break;
      case 1: this._point = 2; this._context.moveTo(this._x4 = x, this._y4 = y); break;
      case 2: this._point = 3; this._x5 = x, this._y5 = y; break;
      default: point$1(this, x, y); break;
    }
    this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
    this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
  }
};

var cardinalClosed = ((function custom(tension) {

  function cardinal(context) {
    return new CardinalClosed(context, tension);
  }

  cardinal.tension = function(tension) {
    return custom(+tension);
  };

  return cardinal;
}))(0);

function CardinalOpen(context, tension) {
  this._context = context;
  this._k = (1 - tension) / 6;
}

CardinalOpen.prototype = {
  areaStart: function() {
    this._line = 0;
  },
  areaEnd: function() {
    this._line = NaN;
  },
  lineStart: function() {
    this._x0 = this._x1 = this._x2 =
    this._y0 = this._y1 = this._y2 = NaN;
    this._point = 0;
  },
  lineEnd: function() {
    if (this._line || (this._line !== 0 && this._point === 3)) this._context.closePath();
    this._line = 1 - this._line;
  },
  point: function(x, y) {
    x = +x, y = +y;
    switch (this._point) {
      case 0: this._point = 1; break;
      case 1: this._point = 2; break;
      case 2: this._point = 3; this._line ? this._context.lineTo(this._x2, this._y2) : this._context.moveTo(this._x2, this._y2); break;
      case 3: this._point = 4; // proceed
      default: point$1(this, x, y); break;
    }
    this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
    this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
  }
};

var cardinalOpen = ((function custom(tension) {

  function cardinal(context) {
    return new CardinalOpen(context, tension);
  }

  cardinal.tension = function(tension) {
    return custom(+tension);
  };

  return cardinal;
}))(0);

function point$2(that, x, y) {
  var x1 = that._x1,
      y1 = that._y1,
      x2 = that._x2,
      y2 = that._y2;

  if (that._l01_a > epsilon) {
    var a = 2 * that._l01_2a + 3 * that._l01_a * that._l12_a + that._l12_2a,
        n = 3 * that._l01_a * (that._l01_a + that._l12_a);
    x1 = (x1 * a - that._x0 * that._l12_2a + that._x2 * that._l01_2a) / n;
    y1 = (y1 * a - that._y0 * that._l12_2a + that._y2 * that._l01_2a) / n;
  }

  if (that._l23_a > epsilon) {
    var b = 2 * that._l23_2a + 3 * that._l23_a * that._l12_a + that._l12_2a,
        m = 3 * that._l23_a * (that._l23_a + that._l12_a);
    x2 = (x2 * b + that._x1 * that._l23_2a - x * that._l12_2a) / m;
    y2 = (y2 * b + that._y1 * that._l23_2a - y * that._l12_2a) / m;
  }

  that._context.bezierCurveTo(x1, y1, x2, y2, that._x2, that._y2);
}

function CatmullRom(context, alpha) {
  this._context = context;
  this._alpha = alpha;
}

CatmullRom.prototype = {
  areaStart: function() {
    this._line = 0;
  },
  areaEnd: function() {
    this._line = NaN;
  },
  lineStart: function() {
    this._x0 = this._x1 = this._x2 =
    this._y0 = this._y1 = this._y2 = NaN;
    this._l01_a = this._l12_a = this._l23_a =
    this._l01_2a = this._l12_2a = this._l23_2a =
    this._point = 0;
  },
  lineEnd: function() {
    switch (this._point) {
      case 2: this._context.lineTo(this._x2, this._y2); break;
      case 3: this.point(this._x2, this._y2); break;
    }
    if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
    this._line = 1 - this._line;
  },
  point: function(x, y) {
    x = +x, y = +y;

    if (this._point) {
      var x23 = this._x2 - x,
          y23 = this._y2 - y;
      this._l23_a = Math.sqrt(this._l23_2a = Math.pow(x23 * x23 + y23 * y23, this._alpha));
    }

    switch (this._point) {
      case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
      case 1: this._point = 2; break;
      case 2: this._point = 3; // proceed
      default: point$2(this, x, y); break;
    }

    this._l01_a = this._l12_a, this._l12_a = this._l23_a;
    this._l01_2a = this._l12_2a, this._l12_2a = this._l23_2a;
    this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
    this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
  }
};

var catmullRom = ((function custom(alpha) {

  function catmullRom(context) {
    return alpha ? new CatmullRom(context, alpha) : new Cardinal(context, 0);
  }

  catmullRom.alpha = function(alpha) {
    return custom(+alpha);
  };

  return catmullRom;
}))(0.5);

function CatmullRomClosed(context, alpha) {
  this._context = context;
  this._alpha = alpha;
}

CatmullRomClosed.prototype = {
  areaStart: noop,
  areaEnd: noop,
  lineStart: function() {
    this._x0 = this._x1 = this._x2 = this._x3 = this._x4 = this._x5 =
    this._y0 = this._y1 = this._y2 = this._y3 = this._y4 = this._y5 = NaN;
    this._l01_a = this._l12_a = this._l23_a =
    this._l01_2a = this._l12_2a = this._l23_2a =
    this._point = 0;
  },
  lineEnd: function() {
    switch (this._point) {
      case 1: {
        this._context.moveTo(this._x3, this._y3);
        this._context.closePath();
        break;
      }
      case 2: {
        this._context.lineTo(this._x3, this._y3);
        this._context.closePath();
        break;
      }
      case 3: {
        this.point(this._x3, this._y3);
        this.point(this._x4, this._y4);
        this.point(this._x5, this._y5);
        break;
      }
    }
  },
  point: function(x, y) {
    x = +x, y = +y;

    if (this._point) {
      var x23 = this._x2 - x,
          y23 = this._y2 - y;
      this._l23_a = Math.sqrt(this._l23_2a = Math.pow(x23 * x23 + y23 * y23, this._alpha));
    }

    switch (this._point) {
      case 0: this._point = 1; this._x3 = x, this._y3 = y; break;
      case 1: this._point = 2; this._context.moveTo(this._x4 = x, this._y4 = y); break;
      case 2: this._point = 3; this._x5 = x, this._y5 = y; break;
      default: point$2(this, x, y); break;
    }

    this._l01_a = this._l12_a, this._l12_a = this._l23_a;
    this._l01_2a = this._l12_2a, this._l12_2a = this._l23_2a;
    this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
    this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
  }
};

var catmullRomClosed = ((function custom(alpha) {

  function catmullRom(context) {
    return alpha ? new CatmullRomClosed(context, alpha) : new CardinalClosed(context, 0);
  }

  catmullRom.alpha = function(alpha) {
    return custom(+alpha);
  };

  return catmullRom;
}))(0.5);

function CatmullRomOpen(context, alpha) {
  this._context = context;
  this._alpha = alpha;
}

CatmullRomOpen.prototype = {
  areaStart: function() {
    this._line = 0;
  },
  areaEnd: function() {
    this._line = NaN;
  },
  lineStart: function() {
    this._x0 = this._x1 = this._x2 =
    this._y0 = this._y1 = this._y2 = NaN;
    this._l01_a = this._l12_a = this._l23_a =
    this._l01_2a = this._l12_2a = this._l23_2a =
    this._point = 0;
  },
  lineEnd: function() {
    if (this._line || (this._line !== 0 && this._point === 3)) this._context.closePath();
    this._line = 1 - this._line;
  },
  point: function(x, y) {
    x = +x, y = +y;

    if (this._point) {
      var x23 = this._x2 - x,
          y23 = this._y2 - y;
      this._l23_a = Math.sqrt(this._l23_2a = Math.pow(x23 * x23 + y23 * y23, this._alpha));
    }

    switch (this._point) {
      case 0: this._point = 1; break;
      case 1: this._point = 2; break;
      case 2: this._point = 3; this._line ? this._context.lineTo(this._x2, this._y2) : this._context.moveTo(this._x2, this._y2); break;
      case 3: this._point = 4; // proceed
      default: point$2(this, x, y); break;
    }

    this._l01_a = this._l12_a, this._l12_a = this._l23_a;
    this._l01_2a = this._l12_2a, this._l12_2a = this._l23_2a;
    this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
    this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
  }
};

var catmullRomOpen = ((function custom(alpha) {

  function catmullRom(context) {
    return alpha ? new CatmullRomOpen(context, alpha) : new CardinalOpen(context, 0);
  }

  catmullRom.alpha = function(alpha) {
    return custom(+alpha);
  };

  return catmullRom;
}))(0.5);

function LinearClosed(context) {
  this._context = context;
}

LinearClosed.prototype = {
  areaStart: noop,
  areaEnd: noop,
  lineStart: function() {
    this._point = 0;
  },
  lineEnd: function() {
    if (this._point) this._context.closePath();
  },
  point: function(x, y) {
    x = +x, y = +y;
    if (this._point) this._context.lineTo(x, y);
    else this._point = 1, this._context.moveTo(x, y);
  }
};

var linearClosed = function(context) {
  return new LinearClosed(context);
};

function sign(x) {
  return x < 0 ? -1 : 1;
}

// Calculate the slopes of the tangents (Hermite-type interpolation) based on
// the following paper: Steffen, M. 1990. A Simple Method for Monotonic
// Interpolation in One Dimension. Astronomy and Astrophysics, Vol. 239, NO.
// NOV(II), P. 443, 1990.
function slope3(that, x2, y2) {
  var h0 = that._x1 - that._x0,
      h1 = x2 - that._x1,
      s0 = (that._y1 - that._y0) / (h0 || h1 < 0 && -0),
      s1 = (y2 - that._y1) / (h1 || h0 < 0 && -0),
      p = (s0 * h1 + s1 * h0) / (h0 + h1);
  return (sign(s0) + sign(s1)) * Math.min(Math.abs(s0), Math.abs(s1), 0.5 * Math.abs(p)) || 0;
}

// Calculate a one-sided slope.
function slope2(that, t) {
  var h = that._x1 - that._x0;
  return h ? (3 * (that._y1 - that._y0) / h - t) / 2 : t;
}

// According to https://en.wikipedia.org/wiki/Cubic_Hermite_spline#Representations
// "you can express cubic Hermite interpolation in terms of cubic Bézier curves
// with respect to the four values p0, p0 + m0 / 3, p1 - m1 / 3, p1".
function point$3(that, t0, t1) {
  var x0 = that._x0,
      y0 = that._y0,
      x1 = that._x1,
      y1 = that._y1,
      dx = (x1 - x0) / 3;
  that._context.bezierCurveTo(x0 + dx, y0 + dx * t0, x1 - dx, y1 - dx * t1, x1, y1);
}

function MonotoneX(context) {
  this._context = context;
}

MonotoneX.prototype = {
  areaStart: function() {
    this._line = 0;
  },
  areaEnd: function() {
    this._line = NaN;
  },
  lineStart: function() {
    this._x0 = this._x1 =
    this._y0 = this._y1 =
    this._t0 = NaN;
    this._point = 0;
  },
  lineEnd: function() {
    switch (this._point) {
      case 2: this._context.lineTo(this._x1, this._y1); break;
      case 3: point$3(this, this._t0, slope2(this, this._t0)); break;
    }
    if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
    this._line = 1 - this._line;
  },
  point: function(x, y) {
    var t1 = NaN;

    x = +x, y = +y;
    if (x === this._x1 && y === this._y1) return; // Ignore coincident points.
    switch (this._point) {
      case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
      case 1: this._point = 2; break;
      case 2: this._point = 3; point$3(this, slope2(this, t1 = slope3(this, x, y)), t1); break;
      default: point$3(this, this._t0, t1 = slope3(this, x, y)); break;
    }

    this._x0 = this._x1, this._x1 = x;
    this._y0 = this._y1, this._y1 = y;
    this._t0 = t1;
  }
};

function MonotoneY(context) {
  this._context = new ReflectContext(context);
}

(MonotoneY.prototype = Object.create(MonotoneX.prototype)).point = function(x, y) {
  MonotoneX.prototype.point.call(this, y, x);
};

function ReflectContext(context) {
  this._context = context;
}

ReflectContext.prototype = {
  moveTo: function(x, y) { this._context.moveTo(y, x); },
  closePath: function() { this._context.closePath(); },
  lineTo: function(x, y) { this._context.lineTo(y, x); },
  bezierCurveTo: function(x1, y1, x2, y2, x, y) { this._context.bezierCurveTo(y1, x1, y2, x2, y, x); }
};

function monotoneX(context) {
  return new MonotoneX(context);
}

function monotoneY(context) {
  return new MonotoneY(context);
}

function Natural(context) {
  this._context = context;
}

Natural.prototype = {
  areaStart: function() {
    this._line = 0;
  },
  areaEnd: function() {
    this._line = NaN;
  },
  lineStart: function() {
    this._x = [];
    this._y = [];
  },
  lineEnd: function() {
    var x = this._x,
        y = this._y,
        n = x.length;

    if (n) {
      this._line ? this._context.lineTo(x[0], y[0]) : this._context.moveTo(x[0], y[0]);
      if (n === 2) {
        this._context.lineTo(x[1], y[1]);
      } else {
        var px = controlPoints(x),
            py = controlPoints(y);
        for (var i0 = 0, i1 = 1; i1 < n; ++i0, ++i1) {
          this._context.bezierCurveTo(px[0][i0], py[0][i0], px[1][i0], py[1][i0], x[i1], y[i1]);
        }
      }
    }

    if (this._line || (this._line !== 0 && n === 1)) this._context.closePath();
    this._line = 1 - this._line;
    this._x = this._y = null;
  },
  point: function(x, y) {
    this._x.push(+x);
    this._y.push(+y);
  }
};

// See https://www.particleincell.com/2012/bezier-splines/ for derivation.
function controlPoints(x) {
  var i,
      n = x.length - 1,
      m,
      a = new Array(n),
      b = new Array(n),
      r = new Array(n);
  a[0] = 0, b[0] = 2, r[0] = x[0] + 2 * x[1];
  for (i = 1; i < n - 1; ++i) a[i] = 1, b[i] = 4, r[i] = 4 * x[i] + 2 * x[i + 1];
  a[n - 1] = 2, b[n - 1] = 7, r[n - 1] = 8 * x[n - 1] + x[n];
  for (i = 1; i < n; ++i) m = a[i] / b[i - 1], b[i] -= m, r[i] -= m * r[i - 1];
  a[n - 1] = r[n - 1] / b[n - 1];
  for (i = n - 2; i >= 0; --i) a[i] = (r[i] - a[i + 1]) / b[i];
  b[n - 1] = (x[n] + a[n - 1]) / 2;
  for (i = 0; i < n - 1; ++i) b[i] = 2 * x[i + 1] - a[i + 1];
  return [a, b];
}

var natural = function(context) {
  return new Natural(context);
};

function Step(context, t) {
  this._context = context;
  this._t = t;
}

Step.prototype = {
  areaStart: function() {
    this._line = 0;
  },
  areaEnd: function() {
    this._line = NaN;
  },
  lineStart: function() {
    this._x = this._y = NaN;
    this._point = 0;
  },
  lineEnd: function() {
    if (0 < this._t && this._t < 1 && this._point === 2) this._context.lineTo(this._x, this._y);
    if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
    if (this._line >= 0) this._t = 1 - this._t, this._line = 1 - this._line;
  },
  point: function(x, y) {
    x = +x, y = +y;
    switch (this._point) {
      case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
      case 1: this._point = 2; // proceed
      default: {
        if (this._t <= 0) {
          this._context.lineTo(this._x, y);
          this._context.lineTo(x, y);
        } else {
          var x1 = this._x * (1 - this._t) + x * this._t;
          this._context.lineTo(x1, this._y);
          this._context.lineTo(x1, y);
        }
        break;
      }
    }
    this._x = x, this._y = y;
  }
};

var step = function(context) {
  return new Step(context, 0.5);
};

function stepBefore(context) {
  return new Step(context, 0);
}

function stepAfter(context) {
  return new Step(context, 1);
}

var none = function(series, order) {
  if (!((n = series.length) > 1)) return;
  for (var i = 1, j, s0, s1 = series[order[0]], n, m = s1.length; i < n; ++i) {
    s0 = s1, s1 = series[order[i]];
    for (j = 0; j < m; ++j) {
      s1[j][1] += s1[j][0] = isNaN(s0[j][1]) ? s0[j][0] : s0[j][1];
    }
  }
};

var none$1 = function(series) {
  var n = series.length, o = new Array(n);
  while (--n >= 0) o[n] = n;
  return o;
};

function stackValue(d, key) {
  return d[key];
}

var stack = function() {
  var keys = constant([]),
      order = none$1,
      offset = none,
      value = stackValue;

  function stack(data) {
    var kz = keys.apply(this, arguments),
        i,
        m = data.length,
        n = kz.length,
        sz = new Array(n),
        oz;

    for (i = 0; i < n; ++i) {
      for (var ki = kz[i], si = sz[i] = new Array(m), j = 0, sij; j < m; ++j) {
        si[j] = sij = [0, +value(data[j], ki, j, data)];
        sij.data = data[j];
      }
      si.key = ki;
    }

    for (i = 0, oz = order(sz); i < n; ++i) {
      sz[oz[i]].index = i;
    }

    offset(sz, oz);
    return sz;
  }

  stack.keys = function(_) {
    return arguments.length ? (keys = typeof _ === "function" ? _ : constant(slice.call(_)), stack) : keys;
  };

  stack.value = function(_) {
    return arguments.length ? (value = typeof _ === "function" ? _ : constant(+_), stack) : value;
  };

  stack.order = function(_) {
    return arguments.length ? (order = _ == null ? none$1 : typeof _ === "function" ? _ : constant(slice.call(_)), stack) : order;
  };

  stack.offset = function(_) {
    return arguments.length ? (offset = _ == null ? none : _, stack) : offset;
  };

  return stack;
};

var expand = function(series, order) {
  if (!((n = series.length) > 0)) return;
  for (var i, n, j = 0, m = series[0].length, y; j < m; ++j) {
    for (y = i = 0; i < n; ++i) y += series[i][j][1] || 0;
    if (y) for (i = 0; i < n; ++i) series[i][j][1] /= y;
  }
  none(series, order);
};

var diverging = function(series, order) {
  if (!((n = series.length) > 1)) return;
  for (var i, j = 0, d, dy, yp, yn, n, m = series[order[0]].length; j < m; ++j) {
    for (yp = yn = 0, i = 0; i < n; ++i) {
      if ((dy = (d = series[order[i]][j])[1] - d[0]) >= 0) {
        d[0] = yp, d[1] = yp += dy;
      } else if (dy < 0) {
        d[1] = yn, d[0] = yn += dy;
      } else {
        d[0] = yp;
      }
    }
  }
};

var silhouette = function(series, order) {
  if (!((n = series.length) > 0)) return;
  for (var j = 0, s0 = series[order[0]], n, m = s0.length; j < m; ++j) {
    for (var i = 0, y = 0; i < n; ++i) y += series[i][j][1] || 0;
    s0[j][1] += s0[j][0] = -y / 2;
  }
  none(series, order);
};

var wiggle = function(series, order) {
  if (!((n = series.length) > 0) || !((m = (s0 = series[order[0]]).length) > 0)) return;
  for (var y = 0, j = 1, s0, m, n; j < m; ++j) {
    for (var i = 0, s1 = 0, s2 = 0; i < n; ++i) {
      var si = series[order[i]],
          sij0 = si[j][1] || 0,
          sij1 = si[j - 1][1] || 0,
          s3 = (sij0 - sij1) / 2;
      for (var k = 0; k < i; ++k) {
        var sk = series[order[k]],
            skj0 = sk[j][1] || 0,
            skj1 = sk[j - 1][1] || 0;
        s3 += skj0 - skj1;
      }
      s1 += sij0, s2 += s3 * sij0;
    }
    s0[j - 1][1] += s0[j - 1][0] = y;
    if (s1) y -= s2 / s1;
  }
  s0[j - 1][1] += s0[j - 1][0] = y;
  none(series, order);
};

var ascending = function(series) {
  var sums = series.map(sum);
  return none$1(series).sort(function(a, b) { return sums[a] - sums[b]; });
};

function sum(series) {
  var s = 0, i = -1, n = series.length, v;
  while (++i < n) if (v = +series[i][1]) s += v;
  return s;
}

var descending$1 = function(series) {
  return ascending(series).reverse();
};

var insideOut = function(series) {
  var n = series.length,
      i,
      j,
      sums = series.map(sum),
      order = none$1(series).sort(function(a, b) { return sums[b] - sums[a]; }),
      top = 0,
      bottom = 0,
      tops = [],
      bottoms = [];

  for (i = 0; i < n; ++i) {
    j = order[i];
    if (top < bottom) {
      top += sums[j];
      tops.push(j);
    } else {
      bottom += sums[j];
      bottoms.push(j);
    }
  }

  return bottoms.reverse().concat(tops);
};

var reverse = function(series) {
  return none$1(series).reverse();
};

exports.arc = arc;
exports.area = area;
exports.line = line;
exports.pie = pie;
exports.areaRadial = areaRadial;
exports.radialArea = areaRadial;
exports.lineRadial = lineRadial$1;
exports.radialLine = lineRadial$1;
exports.pointRadial = pointRadial;
exports.linkHorizontal = linkHorizontal;
exports.linkVertical = linkVertical;
exports.linkRadial = linkRadial;
exports.symbol = symbol;
exports.symbols = symbols;
exports.symbolCircle = circle;
exports.symbolCross = cross;
exports.symbolDiamond = diamond;
exports.symbolSquare = square;
exports.symbolStar = star;
exports.symbolTriangle = triangle;
exports.symbolWye = wye;
exports.curveBasisClosed = basisClosed;
exports.curveBasisOpen = basisOpen;
exports.curveBasis = basis;
exports.curveBundle = bundle;
exports.curveCardinalClosed = cardinalClosed;
exports.curveCardinalOpen = cardinalOpen;
exports.curveCardinal = cardinal;
exports.curveCatmullRomClosed = catmullRomClosed;
exports.curveCatmullRomOpen = catmullRomOpen;
exports.curveCatmullRom = catmullRom;
exports.curveLinearClosed = linearClosed;
exports.curveLinear = curveLinear;
exports.curveMonotoneX = monotoneX;
exports.curveMonotoneY = monotoneY;
exports.curveNatural = natural;
exports.curveStep = step;
exports.curveStepAfter = stepAfter;
exports.curveStepBefore = stepBefore;
exports.stack = stack;
exports.stackOffsetExpand = expand;
exports.stackOffsetDiverging = diverging;
exports.stackOffsetNone = none;
exports.stackOffsetSilhouette = silhouette;
exports.stackOffsetWiggle = wiggle;
exports.stackOrderAscending = ascending;
exports.stackOrderDescending = descending$1;
exports.stackOrderInsideOut = insideOut;
exports.stackOrderNone = none$1;
exports.stackOrderReverse = reverse;

Object.defineProperty(exports, '__esModule', { value: true });

})));

},{"d3-path":2}]},{},[1]);

index.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
    <title>Graphing audio</title>
  </head>

  <body>
    <audio id="audioElement" src="./music.mp3"></audio>
 <script src="app.js"></script>
  </body>
</html>

index.js

var d3_shape = require("d3-shape");
var d3_selection = require("d3-selection");

var width = 500;
var height = 500;
var dataPerLine = 30;
var lines = 60;
var playing = false;

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
    var audioElement = document.getElementById('audioElement');
    var audioSrc = audioCtx.createMediaElementSource(audioElement);
    var analyser = audioCtx.createAnalyser();

    audioSrc.connect(analyser);
    audioSrc.connect(audioCtx.destination);

    var frequencyData = new Uint8Array(lines);


var canvas = d3_selection.select("body")
    .append("canvas")
    .attr('height', height)
    .attr('width', width);

var context = canvas.node().getContext("2d");

var line = d3_shape.line()
    .x(function(d, i){return width/4 + (i/dataPerLine)*width/2;})
    .y(function(d, i){return -d * Math.sin(Math.PI * i/dataPerLine);})
    .context(context);

var area = d3_shape.area()
    .x(function(d, i){return width/4 + (i/dataPerLine)*width/2;})
    .y1(function(d, i){return -d * Math.sin(Math.PI * i/dataPerLine);})
    .y0(40)
    .context(context);


var data = [];
for (var i = 0; i < lines; i++) {
    var dataElements = [];
    for (var j = 0; j < dataPerLine; j++) {
        dataElements.push(0);
    }
    data.push(dataElements);
  }

 

function renderChart() {
     requestAnimationFrame(renderChart);

     // Copy frequency data to frequencyData array.
     analyser.getByteFrequencyData(frequencyData);
     for(var i = 0; i < lines; i++){
         data[i].push(frequencyData[i]);
         data[i].shift();
     }

    
    context.fillStyle = "black";
    context.fillRect(0, 0, width, height);

    context.lineWidth = 1.6;
    context.strokeStyle = "#dddddd";
    context.fillStyle = "#000000";
    for(var i = 0; i < lines; i++){
            context.save();

            context.translate(0,((height/5) + (i/lines)*3*height/5));
            context.beginPath();
            area(data[i].map(function(curr, i, arr){return i>0?curr - arr[i-1]:0;}));
            context.fill();
            context.beginPath();
            line(data[i].map(function(curr, i, arr){return i>0?curr - arr[i-1]:0;}));
            context.stroke();


            context.restore();
        }

  }

  // Run the loop
  renderChart();
 
  canvas.on("click", togglePlay);
  

  function togglePlay(){
    if(playing===false){
        audioElement.play();
        playing = true;
    } else {
        audioElement.pause();
        playing = false;
    }
  }

  togglePlay();
  

music.mp3

thumbnail.png