msbarry · March 21, 2017 19:18
diff --git a/index.html b/index.html
 <!DOCTYPE html>
 <html>
  <head>
    <meta http-equiv="Content-Type" content="text/html;charset=utf-8"/>
    <title>M/M/1 Queue</title>
    <style type="text/css">
 body {
  font-size: 12px;
  font-family: Arial;
  width: 960px;
  margin: 1em auto 0.3em auto;
 }

 .controls {
  margin: 20px 0 0 20px;
 }

 #chart {
  width: 100%;
  margin-top: 10px;
 }

 #chart svg {
  margin-top: 10px;
 }

 .notshown {
  margin-left: 20px;
 }

 svg .bounds {
  fill-opacity: 0;
  stroke-opacity: 1;
  stroke: #000;
  shape-rendering: crispEdges;
 }

    </style>
  </head>
  <body>
    <div class="controls">
      <p>Arrivals per second: <input type="number" step="0.1" value="1" id="arr"></input>
      Seconds to service: <input type="number" step="0.1" value="0.5" id="ts"></input></p>
    </div>
    <div id="chart"></div>
    <script src="http://d3js.org/d3.v3.min.js" charset="utf-8"></script>
    <script>
 var margin = {top: 1, right: 20, bottom: 1, left: 20},
    outerWidth = 970,
    outerHeight = 35,
    w = outerWidth - margin.left - margin.right,
    h = outerHeight - margin.top - margin.bottom;

 var packetPadding = 3,
    packetWidth = 30,
    packetHeight = h - 2 * packetPadding,
    limit = Math.floor(w / (packetWidth + packetPadding)) - 1;

 var color = d3.scale.pow().exponent(4)
  .domain([limit, 0])
  .range(["red", "black"])
  .interpolate(d3.interpolateLab);

 d3.range(0, 5).forEach(function () {
  var id = 0, queue = [];

  var svg = d3.select("#chart")
    .append("svg")
      .attr("width", outerWidth)
      .attr("height", outerHeight)
    .append("g")
      .attr("transform", "translate(" + [margin.left, margin.top].join(",") + ")");

  svg.append("rect")
      .attr("class", "bounds")
      .attr("width", packetWidth + packetPadding)
      .attr("height", packetHeight + packetPadding)
      .attr("x", w - packetWidth - packetPadding * 1.5)
      .attr("y", 1);

  function schedulePoisson(f, averageRatePerSecond) {
    var delay = (1000 * -Math.log(Math.random()) / averageRatePerSecond) || 1000;
    setTimeout(f, delay);
  }

  function packetArrival() {
    queue.push(id++);
    updateUI();
    if (queue.length === 1) { schedulePoisson(servicePacket, 1 / averageServiceTimeInSeconds()); }
    updateNotShown(queue);
    schedulePoisson(packetArrival, arrivalRatePerSecond());
  }

  function servicePacket() {
    queue.shift(1);
    updateUI();
    updateNotShown(queue);
    if (queue.length > 0) { schedulePoisson(servicePacket, 1 / averageServiceTimeInSeconds()); }
  }

  function updateUI() {
    var rects = svg.selectAll(".packet")
      .data(queue.slice(0, limit + 1), function (d) { return d; });

    // restyle existing packets
    rects.transition()
        .call(stylePacket);

    // add new packets
    rects.enter().append("rect")
        .attr("class", "packet")
        .attr("width", packetWidth)
        .attr("height", packetHeight)
        .attr("x", -packetWidth)
        .attr("y", packetPadding)
      .transition()
        .call(stylePacket);

    // get ride of old packets
    rects.exit()
        .transition()
        .attr("x", w + 1000)
        .remove();
  }

  var notShown = d3.select("#chart").append("p")
      .html("&nbsp;")
      .attr("class", "notshown");

  function updateNotShown() {
    if (queue.length > limit) {
      notShown.text((queue.length - limit) + " not shown");
    } else {
      notShown.html("&nbsp;");
    }
  }

  // start the simulation
  schedulePoisson(packetArrival, arrivalRatePerSecond());
 });

 function stylePacket(packet) {
  packet
      .ease('cubic-out')
      .attr("x", function (d, i) { return w - (packetWidth + packetPadding) * (i + 1); })
      .attr("fill", function (d, i) { return i === 0 ? "blue" : color(i); });
 };

 function averageServiceTimeInSeconds() {
  return +d3.select("#ts").node().value;
 }

 function arrivalRatePerSecond() {
  return +d3.select("#arr").node().value;
 }

    </script>
  </body>
 </html>
diff --git a/thumbnail.png b/thumbnail.png
	<!DOCTYPE html>
	<html>
	<head>
	<meta http-equiv="Content-Type" content="text/html;charset=utf-8"/>
	<title>M/M/1 Queue</title>
	<style type="text/css">
	body {
	font-size: 12px;
	font-family: Arial;
	width: 960px;
	margin: 1em auto 0.3em auto;
	}

	.controls {
	margin: 20px 0 0 20px;
	}

	#chart {
	width: 100%;
	margin-top: 10px;
	}

	#chart svg {
	margin-top: 10px;
	}

	.notshown {
	margin-left: 20px;
	}

	svg .bounds {
	fill-opacity: 0;
	stroke-opacity: 1;
	stroke: #000;
	shape-rendering: crispEdges;
	}

	</style>
	</head>
	<body>
	<div class="controls">
	<p>Arrivals per second: <input type="number" step="0.1" value="1" id="arr"></input>
	Seconds to service: <input type="number" step="0.1" value="0.5" id="ts"></input></p>
	</div>
	<div id="chart"></div>
	<script src="http://d3js.org/d3.v3.min.js" charset="utf-8"></script>
	<script>
	var margin = {top: 1, right: 20, bottom: 1, left: 20},
	outerWidth = 970,
	outerHeight = 35,
	w = outerWidth - margin.left - margin.right,
	h = outerHeight - margin.top - margin.bottom;

	var packetPadding = 3,
	packetWidth = 30,
	packetHeight = h - 2 * packetPadding,
	limit = Math.floor(w / (packetWidth + packetPadding)) - 1;

	var color = d3.scale.pow().exponent(4)
	.domain([limit, 0])
	.range(["red", "black"])
	.interpolate(d3.interpolateLab);

	d3.range(0, 5).forEach(function () {
	var id = 0, queue = [];

	var svg = d3.select("#chart")
	.append("svg")
	.attr("width", outerWidth)
	.attr("height", outerHeight)
	.append("g")
	.attr("transform", "translate(" + [margin.left, margin.top].join(",") + ")");

	svg.append("rect")
	.attr("class", "bounds")
	.attr("width", packetWidth + packetPadding)
	.attr("height", packetHeight + packetPadding)
	.attr("x", w - packetWidth - packetPadding * 1.5)
	.attr("y", 1);

	function schedulePoisson(f, averageRatePerSecond) {
	var delay = (1000 * -Math.log(Math.random()) / averageRatePerSecond) \|\| 1000;
	setTimeout(f, delay);
	}

	function packetArrival() {
	queue.push(id++);
	updateUI();
	if (queue.length === 1) { schedulePoisson(servicePacket, 1 / averageServiceTimeInSeconds()); }
	updateNotShown(queue);
	schedulePoisson(packetArrival, arrivalRatePerSecond());
	}

	function servicePacket() {
	queue.shift(1);
	updateUI();
	updateNotShown(queue);
	if (queue.length > 0) { schedulePoisson(servicePacket, 1 / averageServiceTimeInSeconds()); }
	}

	function updateUI() {
	var rects = svg.selectAll(".packet")
	.data(queue.slice(0, limit + 1), function (d) { return d; });

	// restyle existing packets
	rects.transition()
	.call(stylePacket);

	// add new packets
	rects.enter().append("rect")
	.attr("class", "packet")
	.attr("width", packetWidth)
	.attr("height", packetHeight)
	.attr("x", -packetWidth)
	.attr("y", packetPadding)
	.transition()
	.call(stylePacket);

	// get ride of old packets
	rects.exit()
	.transition()
	.attr("x", w + 1000)
	.remove();
	}

	var notShown = d3.select("#chart").append("p")
	.html(" ")
	.attr("class", "notshown");

	function updateNotShown() {
	if (queue.length > limit) {
	notShown.text((queue.length - limit) + " not shown");
	} else {
	notShown.html(" ");
	}
	}

	// start the simulation
	schedulePoisson(packetArrival, arrivalRatePerSecond());
	});

	function stylePacket(packet) {
	packet
	.ease('cubic-out')
	.attr("x", function (d, i) { return w - (packetWidth + packetPadding) * (i + 1); })
	.attr("fill", function (d, i) { return i === 0 ? "blue" : color(i); });
	};

	function averageServiceTimeInSeconds() {
	return +d3.select("#ts").node().value;
	}

	function arrivalRatePerSecond() {
	return +d3.select("#arr").node().value;
	}

	</script>
	</body>
	</html>