var bardata = []

for (var i =0; i < 100; i++) {
	bardata.push(Math.random()*30)
}

var height = 400,
    width = 600,
    barWidth = 50,
    barOffset = 5;

// var colors = d3.scale.linear()
// 	.domain([0, d3.max(bardata)])
// 	.range(['blue', 'green'])

var colors = d3.scale.linear()
	.domain([0, bardata.length*.33, bardata.length*.66, bardata.length])
	.range(['blue', 'orange', 'red', 'purple'])

var yScale = d3.scale.linear()
	.domain([0, d3.max(bardata)])
	.range([0, height])

var xScale = d3.scale.ordinal()
	.domain(d3.range(0, bardata.length))
	.rangeBands([0, width])

d3.select('#chart')
	.append('svg')
		.attr('width', width)
		.attr('height', height)
// 		.style('background', 'yellow')
	.selectAll('rect')
		.data(bardata)
		.enter().append('rect')
			.style('fill', function(d, i){
  			return colors(i)
			})
			.attr('width', xScale.rangeBand())
			.attr('height', function(d){
  			return yScale(d);
			})
			.attr('x', function(d, i){
  			return xScale(i);
			})
			.attr('y', function(d){
            	return height - yScale(d);
            })