bmershon/.block

## .block
height: 2000
border: no
license: MIT

## README.md

      
    Raw
  

              README.md
            
          
    See Hofstadter's Chaotic Sequence Q.

  
## hofstadter.js
(function() {
  var Hofstadter;

  // Hofstadter's chaotic function Q
  // computed using a dynamic programming
  function q(n) {
    var A = [],
        i;

    A[0] = 0
    A[1] = 1;
    A[2] = 1;

    for (i = 3; i <= n; i++) {
      A[i] = A[i - A[i - 1]] + A[i - A[i - 2]];
    }

    return A[n];
  }

  Hofstadter = {};
  Hofstadter.function = {};
  Hofstadter.function.Q = q;

  d3.Hofstadter = Hofstadter;
})();

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

.node circle {
  fill: #000;
}

.node text {
  font: 11px sans-serif;
}

.node--internal text {
  text-shadow: 0 1px 0 #fff, 0 -1px 0 #fff, 1px 0 0 #fff, -1px 0 0 #fff;
}

.link {
  fill: none;
  stroke-width: 2px;
  stroke-opacity: 1;
}

</style>
<svg width="960" height="2000"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script src="https://d3js.org/d3-scale-chromatic.v1.min.js"></script>
<script src="hofstadter.js"></script>
<script>

var svg = d3.select("svg"),
    node, link,
    width = +svg.attr("width"),
    height = +svg.attr("height"),
    padding = 50;

var tree, root,
    N = 300,
    color, y, max;

svg = svg
    .attr("width", width)
    .attr("height", height)
  .append("g")
    .attr("transform", "translate(" + padding / 2 + ",0)");

y = d3.scaleLinear().domain([1, N]).range([height, 0]);

color = d3.interpolateRdBu;

sequence = d3.range(N).map(function(d, i) {
  return d3.Hofstadter.function.Q(i);
});

data = sequence.slice(1).map(function(d, i) {
  var parent = (i === 0) ? "" : d;
  return {name: "" + (i + 1), parent: "" + parent};
});

max = d3.max(sequence, function(d, i) {
  return Math.abs(d - i);
});

root = d3.stratify()
    .id(function(d) { return d.name; })
    .parentId(function(d) { return d.parent; })
    (data);

tree = d3.tree()
    .size([width - padding, height - padding])
    (root);

link = svg.selectAll(".link")
    .data(root.descendants().slice(1))
  .enter().append("path")
    .attr("class", "link")
    .attr("stroke", colorize)
    .attr("d", spline);

function colorize(d) {
  return color(Math.abs(+d.data.name - +d.data.parent) / max);
}

function spline(d) {
  return "M" + d.x + "," + y(+d.data.name)
          + "C" + (d.x + d.parent.x) / 2 + "," + y(+d.data.name)
          + " " + (d.x + d.parent.x) / 2 + "," + y(+d.parent.data.name)
          + " " + d.parent.x + "," + y(+d.parent.data.name);
}

node = svg.selectAll(".node")
      .data(root.descendants())
    .enter().append("g")
      .attr("class", "node")
      .attr("transform", function(d) { return "translate(" + d.x + "," + y(+d.data.name) + ")"; });

node.append("circle")
    .attr("r", 2);
</script>

## thumbnail.png

      
    Raw
  

              thumbnail.png
            
          
## worker.js
importScripts('https://d3js.org/d3-array.v1.min.js');
importScripts('https://d3js.org/d3-hierarchy.v1.min.js');
importScripts('hofstadter.js');

onmessage = function(event) {
  var sequence = d3.range(event.data.N).map(function(d, i) {
    postMessage({type: "tick", progress: i / (100 * 3)});
    return d3.Hofstadter.function.Q(i);
  });

  var structure = sequence.slice(1).map(function(d, i) {
    postMessage({type: "tick", progress: i / (100 * 3)});
    var parent = (i === 0) ? "" : d;
    return {name: "" + (i + 1), parent: "" + parent};
  });

  var max = d3.max(sequence, function(d, i) {
    postMessage({type: "tick", progress: i / (100 * 3)});
    return Math.abs(d - i);
  });

  var root = d3.stratify()
      .id(function(d) { return d.name; })
      .parentId(function(d) { return d.parent; })
      (structure);

  postMessage({type: "end", root: root});
};
	(function() {
	var Hofstadter;

	// Hofstadter's chaotic function Q
	// computed using a dynamic programming
	function q(n) {
	var A = [],
	i;

	A[0] = 0
	A[1] = 1;
	A[2] = 1;

	for (i = 3; i <= n; i++) {
	A[i] = A[i - A[i - 1]] + A[i - A[i - 2]];
	}

	return A[n];
	}

	Hofstadter = {};
	Hofstadter.function = {};
	Hofstadter.function.Q = q;

	d3.Hofstadter = Hofstadter;
	})();
	<!DOCTYPE html>
	<meta charset="utf-8">
	<style>

	.node circle {
	fill: #000;
	}

	.node text {
	font: 11px sans-serif;
	}

	.node--internal text {
	text-shadow: 0 1px 0 #fff, 0 -1px 0 #fff, 1px 0 0 #fff, -1px 0 0 #fff;
	}

	.link {
	fill: none;
	stroke-width: 2px;
	stroke-opacity: 1;
	}

	</style>
	<svg width="960" height="2000"></svg>
	<script src="https://d3js.org/d3.v4.min.js"></script>
	<script src="https://d3js.org/d3-scale-chromatic.v1.min.js"></script>
	<script src="hofstadter.js"></script>
	<script>

	var svg = d3.select("svg"),
	node, link,
	width = +svg.attr("width"),
	height = +svg.attr("height"),
	padding = 50;

	var tree, root,
	N = 300,
	color, y, max;

	svg = svg
	.attr("width", width)
	.attr("height", height)
	.append("g")
	.attr("transform", "translate(" + padding / 2 + ",0)");

	y = d3.scaleLinear().domain([1, N]).range([height, 0]);

	color = d3.interpolateRdBu;

	sequence = d3.range(N).map(function(d, i) {
	return d3.Hofstadter.function.Q(i);
	});

	data = sequence.slice(1).map(function(d, i) {
	var parent = (i === 0) ? "" : d;
	return {name: "" + (i + 1), parent: "" + parent};
	});

	max = d3.max(sequence, function(d, i) {
	return Math.abs(d - i);
	});

	root = d3.stratify()
	.id(function(d) { return d.name; })
	.parentId(function(d) { return d.parent; })
	(data);

	tree = d3.tree()
	.size([width - padding, height - padding])
	(root);

	link = svg.selectAll(".link")
	.data(root.descendants().slice(1))
	.enter().append("path")
	.attr("class", "link")
	.attr("stroke", colorize)
	.attr("d", spline);

	function colorize(d) {
	return color(Math.abs(+d.data.name - +d.data.parent) / max);
	}

	function spline(d) {
	return "M" + d.x + "," + y(+d.data.name)
	+ "C" + (d.x + d.parent.x) / 2 + "," + y(+d.data.name)
	+ " " + (d.x + d.parent.x) / 2 + "," + y(+d.parent.data.name)
	+ " " + d.parent.x + "," + y(+d.parent.data.name);
	}

	node = svg.selectAll(".node")
	.data(root.descendants())
	.enter().append("g")
	.attr("class", "node")
	.attr("transform", function(d) { return "translate(" + d.x + "," + y(+d.data.name) + ")"; });

	node.append("circle")
	.attr("r", 2);
	</script>
	importScripts('https://d3js.org/d3-array.v1.min.js');
	importScripts('https://d3js.org/d3-hierarchy.v1.min.js');
	importScripts('hofstadter.js');

	onmessage = function(event) {
	var sequence = d3.range(event.data.N).map(function(d, i) {
	postMessage({type: "tick", progress: i / (100 * 3)});
	return d3.Hofstadter.function.Q(i);
	});

	var structure = sequence.slice(1).map(function(d, i) {
	postMessage({type: "tick", progress: i / (100 * 3)});
	var parent = (i === 0) ? "" : d;
	return {name: "" + (i + 1), parent: "" + parent};
	});

	var max = d3.max(sequence, function(d, i) {
	postMessage({type: "tick", progress: i / (100 * 3)});
	return Math.abs(d - i);
	});

	var root = d3.stratify()
	.id(function(d) { return d.name; })
	.parentId(function(d) { return d.parent; })
	(structure);

	postMessage({type: "end", root: root});
	};