kinjouj · October 9, 2013 11:28
diff --git a/index.html b/index.html
 <html>
  <head>
    <script type="text/javascript" src="underscore.js"></script>
  </head>
  <body>
    <canvas id="canvas" width="700" height="600"></canvas>
    <script type="text/javascript">
 var canvas = document.getElementById('canvas');
 var context = canvas.getContext('2d');

 var xaxis_margin = 20;
 var yaxis_margin = 50;

 var max_width = canvas.width - yaxis_margin;
 var max_height = canvas.height - xaxis_margin;

 var values = _.times(
  _.random(15, 8),
  function() {
    return Math.ceil(_.random(100, 999) / 100) * 100;
  }
 );

 var max_value = Math.ceil(_.max(values) / 100) * 100;
 var percentage = max_value / max_height;
 var bar_width = (Math.floor(max_width / values.length / 10) * 10) / 2;

 context.beginPath();
 context.lineWidth = 1;
 context.globalAlpha = 0.5;
 context.moveTo(20, 0);
 context.lineTo(20, max_height);
 context.lineTo(max_width, max_height);
 context.stroke();

 values.forEach(drawBar);

 _.range(0, max_value, 100).forEach(function(num) {
  // バーの高さをpercentageで割った値を更に75%の比率で縮小させているので、目盛りの位置もそれと同様に縮小させる。更にそれに
  num /= percentage;
  num *= 0.75;
  num += 100 + yaxis_margin;

  context.beginPath();
  context.lineWidth = 0.5;
  context.strokeStyle = '#000';
  context.moveTo(15, num);
  context.lineTo(25, num);
  context.stroke();
 });

 var prevX = 0;
 var prevY = 0;

 function drawBar(value, count) {
  var pValue = value / percentage * 0.75;
  var x = count * bar_width * 2;
  var y = max_height - pValue;
  var top_center = x + yaxis_margin + bar_width / 2;

  context.beginPath();
  context.fillStyle = 'rgb(27, 188, 155)';
  context.shadowColor = "#999";
  context.globalAlpha = 1;
  context.fillRect(x + yaxis_margin, y, bar_width, pValue);

  context.beginPath();
  context.moveTo(top_center, y);
  context.lineTo(prevX + yaxis_margin + bar_width / 2, prevY);
  context.lineWidth = 3;
  context.globalAlpha = 0.2;
  context.strokeStyle = "rgb(0, 0, 255)";
  context.stroke();

  context.beginPath();
  context.fillStyle = 'rgb(255, 0, 0)';
  context.globalAlpha = 1;
  context.arc(top_center, y, 5, 0, Math.PI * 2, true);
  context.fill();

  context.beginPath();
  context.fillStyle = 'rgb(255, 0, 255)';
  context.fillText(value, top_center - 10, y - yaxis_margin / 2);

  context.beginPath();
  context.fillStyle = 'rgb(0, 0, 0)';
  context.fillText(count + 1, top_center - 5, max_height + xaxis_margin);

  prevX = x;
  prevY = y;
 }
    </script>
  </body>
 </html>
	<html>
	<head>
	<script type="text/javascript" src="underscore.js"></script>
	</head>
	<body>
	<canvas id="canvas" width="700" height="600"></canvas>
	<script type="text/javascript">
	var canvas = document.getElementById('canvas');
	var context = canvas.getContext('2d');

	var xaxis_margin = 20;
	var yaxis_margin = 50;

	var max_width = canvas.width - yaxis_margin;
	var max_height = canvas.height - xaxis_margin;

	var values = _.times(
	_.random(15, 8),
	function() {
	return Math.ceil(_.random(100, 999) / 100) * 100;
	}
	);

	var max_value = Math.ceil(_.max(values) / 100) * 100;
	var percentage = max_value / max_height;
	var bar_width = (Math.floor(max_width / values.length / 10) * 10) / 2;

	context.beginPath();
	context.lineWidth = 1;
	context.globalAlpha = 0.5;
	context.moveTo(20, 0);
	context.lineTo(20, max_height);
	context.lineTo(max_width, max_height);
	context.stroke();

	values.forEach(drawBar);

	_.range(0, max_value, 100).forEach(function(num) {
	// バーの高さをpercentageで割った値を更に75%の比率で縮小させているので、目盛りの位置もそれと同様に縮小させる。更にそれに
	num /= percentage;
	num *= 0.75;
	num += 100 + yaxis_margin;

	context.beginPath();
	context.lineWidth = 0.5;
	context.strokeStyle = '#000';
	context.moveTo(15, num);
	context.lineTo(25, num);
	context.stroke();
	});

	var prevX = 0;
	var prevY = 0;

	function drawBar(value, count) {
	var pValue = value / percentage * 0.75;
	var x = count * bar_width * 2;
	var y = max_height - pValue;
	var top_center = x + yaxis_margin + bar_width / 2;

	context.beginPath();
	context.fillStyle = 'rgb(27, 188, 155)';
	context.shadowColor = "#999";
	context.globalAlpha = 1;
	context.fillRect(x + yaxis_margin, y, bar_width, pValue);

	context.beginPath();
	context.moveTo(top_center, y);
	context.lineTo(prevX + yaxis_margin + bar_width / 2, prevY);
	context.lineWidth = 3;
	context.globalAlpha = 0.2;
	context.strokeStyle = "rgb(0, 0, 255)";
	context.stroke();

	context.beginPath();
	context.fillStyle = 'rgb(255, 0, 0)';
	context.globalAlpha = 1;
	context.arc(top_center, y, 5, 0, Math.PI * 2, true);
	context.fill();

	context.beginPath();
	context.fillStyle = 'rgb(255, 0, 255)';
	context.fillText(value, top_center - 10, y - yaxis_margin / 2);

	context.beginPath();
	context.fillStyle = 'rgb(0, 0, 0)';
	context.fillText(count + 1, top_center - 5, max_height + xaxis_margin);

	prevX = x;
	prevY = y;
	}
	</script>
	</body>
	</html>