rangeRoundBands v rangeBands

I was confused how rangeRoundBands differed from rangeBands so made this example

<!DOCTYPE html>
<html>
<head>
	<title>Ordinal scale - rangeRoundBands</title>
	<style type="text/css">
		body {
			text-align: center;
		}
		svg {
			border: 1px solid #f90;
			margin: 32px;
		}
	</style>
</head>
<body>

var svg = d3.select('svg')
						.attr('width', width)
						.attr('height', height)

var data = d3.range(51)

var x = d3.scale.ordinal()
					.domain(data)
					.rangeRoundBands([0, width])

var colors = d3.scale.category20()

svg.selectAll('rect.example1')
			.data(data)
			.enter()
				.append('rect')
					.attr('class', 'example1')
					.style('fill', colors)
					.attr('x', function(d) { return x(d) })
					.attr('y', 50)
					.attr('width', x.rangeBand())
					.attr('height', 50)

var x = d3.scale.ordinal()
					.domain(data)
					.rangeBands([0, width])

svg.selectAll('rect.example2')
			.data(data)
			.enter()
				.append('rect')
					.attr('class', 'example2')
					.style('fill', colors)
					.attr('x', function(d) { return Math.round(x(d)) })
					.attr('y', 150)
					.attr('width', Math.round(x.rangeBand()))
					.attr('height', 50)

</script>

</body>
</html>

Modified http://d3js.org/d3.v3.min.js to a secure url

https://d3js.org/d3.v3.min.js