var margin = 0, width = 600, height = 600, maxBarHeight = height / 2 - (margin); var innerRadius = 0.4 * maxBarHeight; // innermost circle var svg = d3.select('#today_chart') .append("svg") .attr("width", width) .attr("height", height) .append("g") .attr("class", "chart") .attr("transform", "translate(" + width / 2 + "," + height / 2 + ")");..