gistfile1.txt

var arrows = d3.selectAll(".g-chart--reported svg").append("g").attr("class","arrows").selectAll("rect").data(d3.range(12)).enter().append("rect"),bars = d3.selectAll(".g-chart--reported svg rect.g-bar"),scale = d3.scale.linear().range([80,10]),newData = bars.data().map(function(d,i){ return d; }); arrows.attr("x",function(d,i){ return +bars.filter(function(f,j){ return j == i; }).attr("x")+3; }).attr("width",function(d,i){ return +bars.filter(function(f,j){ return j == i; }).attr("width")-6; }); setInterval(function(){newData = bars.data().map(function(d,i){ return d; }); newData = newData.map(function(d,i){ return i % 12 ? d.reported - newData[i-1].reported : null;}); scale.domain(d3.extent(newData.filter(function(d){return d !== null;}))); arrows.data(newData).style("fill",function(d){ return d < 0 ? "firebrick" : "steelblue"; }).attr("y",function(d){ return d < 0 ? scale(0) : scale(d); }).attr("height",function(d){ return d < 0 ? scale(d) - scale(0) : scale(0) - scale(d); })},200);