barStack - stacking with negative values

<!DOCTYPE html>
<html>
<head>
<script src="https://cdn.jsdelivr.net/npm/d3@2.10.3/d3.v2.js"></script>
<title>barStack</title>  
<style>
.axis text {
  font: 10px sans-serif;
}
.axis path, .axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}
</style>
</head>
<body>
<script type="text/javascript" >
function barStack(d) {
	var l = d[0].length
	while (l--) {
		var posBase = 0, negBase = 0;
		d.forEach(function(d) {
			d=d[l]
			d.size = Math.abs(d.y)
			if (d.y<0)  {
				d.y0 = negBase
				negBase-=d.size
			} else
			{ 
				d.y0 = posBase = posBase + d.size
			} 
		})
	}
	d.extent= d3.extent(d3.merge(d3.merge(d.map(function(e) { return e.map(function(f) { return [f.y0,f.y0-f.size]})}))))
	return d
}

/* Here is an example */

var data = [[{y:300},{y:600},{y:-300}],
			[{y:400},{y:-200},{y:-900}],
                        [{y:100},{y:-100},{y:-100}],
			[{y:1000},{y:-300},{y:400}]]

var  h=500
	,w=500
	,margin=10
	,color = d3.scale.category10()

,x = d3.scale.ordinal()
		.domain(d3.range(data[0].length+1))
		.rangeRoundBands([margin,w-margin], .1)

,y = d3.scale.linear()
		.range([h-margin,0+margin])

,xAxis = d3.svg.axis().scale(x).orient("bottom").tickSize(6, 0)
	,yAxis = d3.svg.axis().scale(y).orient("left")
	
barStack(data)
console.log(data)
y.domain(data.extent)

svg = d3.select("body")
	.append("svg")
	.attr("height",h)
	.attr("width",w)

svg.selectAll(".series").data(data)
	.enter().append("g").classed("series",true).style("fill", function(d,i) { return color(i)})
		.selectAll("rect").data(Object)
		.enter().append("rect")
			.attr("x",function(d,i) { return x(i)})
			.attr("y",function(d) { return y(d.y0)})
			.attr("height",function(d) { console.log(d);
console.log(y(0)-y(d.size));
return y(0)-y(d.size)})
			.attr("width",x.rangeBand())

svg.append("g").attr("class","axis x").attr("transform","translate (0 "+y(0)+")").call(xAxis)
svg.append("g").attr("class","axis y").attr("transform","translate ("+x(margin)+" 0)").call(yAxis)

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

Modified http://mbostock.github.com/d3/d3.v2.js to a secure url

https://mbostock.github.com/d3/d3.v2.js