d3导出svg图片

var svgHeadInfo = '<?xml version="1.0" encoding="UTF-8"?>\n<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.0//EN"\n"http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">';
            var svg = $('#vizContainer').find('svg')[0];
            svg.setAttribute("xmlns:xlink", "http://www.w3.org/1999/xlink");

            var svgSource = d3.select("svg")
                .attr("version", 1.1)
                .attr("xmlns", "http://www.w3.org/2000/svg")
                .node().parentNode.innerHTML;

            d3.select("body").append("a")
                .attr("title", "file.svg")
                .attr("href-lang", "image/svg+xml")
                .attr("href", "data:image/svg+xml;base64," + btoa(unescape(encodeURIComponent(svgHeadInfo + svgSource))))
                .text("Download");