D3.js是一个JavaScript库，它可以通过数据来操作文档。D3可以通过使用HTML、SVG和CSS把数据鲜活形象地展现出来。D3严格遵循Web标准，因而可以让你的程序轻松兼容现代主流浏览器并避免对特定框架的依赖。同时，它提供了强大的可视化组件，可以让使用者以数据驱动的方式去操作DOM。（来自：维基百科D3.js词条）

!function(){

var Donut3D={};

function pieTop(d, rx, ry, ir ){

if(d.endAngle - d.startAngle == 0 ) return "M 0 0";

var sx = rx*Math.cos(d.startAngle),

sy = ry*Math.sin(d.startAngle),

ex = rx*Math.cos(d.endAngle),

ey = ry*Math.sin(d.endAngle);

var ret =[];

ret.push("M",sx,sy,"A",rx,ry,"0",(d.endAngle-d.startAngle > Math.PI? 1: 0),"1",ex,ey,"L",ir*ex,ir*ey);

ret.push("A",ir*rx,ir*ry,"0",(d.endAngle-d.startAngle > Math.PI? 1: 0), "0",ir*sx,ir*sy,"z");

return ret.join(" ");

}

function pieOuter(d, rx, ry, h ){

var startAngle = (d.startAngle > Math.PI ? Math.PI : d.startAngle);

var endAngle = (d.endAngle > Math.PI ? Math.PI : d.endAngle);

var sx = rx*Math.cos(startAngle),

sy = ry*Math.sin(startAngle),

ex = rx*Math.cos(endAngle),

ey = ry*Math.sin(endAngle);

var ret =[];

ret.push("M",sx,h+sy,"A",rx,ry,"0 0 1",ex,h+ey,"L",ex,ey,"A",rx,ry,"0 0 0",sx,sy,"z");

return ret.join(" ");

}

function pieInner(d, rx, ry, h, ir ){

var startAngle = (d.startAngle < Math.PI ? Math.PI : d.startAngle);

var endAngle = (d.endAngle < Math.PI ? Math.PI : d.endAngle);

var sx = ir*rx*Math.cos(startAngle),

sy = ir*ry*Math.sin(startAngle),

ex = ir*rx*Math.cos(endAngle),

ey = ir*ry*Math.sin(endAngle);

var ret =[];

ret.push("M",sx, sy,"A",ir*rx,ir*ry,"0 0 1",ex,ey, "L",ex,h+ey,"A",ir*rx, ir*ry,"0 0 0",sx,h+sy,"z");

return ret.join(" ");

}

function getPercent(d){

return (d.endAngle-d.startAngle > 0.2 ?

Math.round(1000*(d.endAngle-d.startAngle)/(Math.PI*2))/10+'%' : '');

}

Donut3D.transition = function(id, data, rx, ry, h, ir){

function arcTweenInner(a) {

  var i = d3.interpolate(this._current, a);

  this._current = i(0);

  return function(t) { return pieInner(i(t), rx+0.5, ry+0.5, h, ir);  };

}

function arcTweenTop(a) {

  var i = d3.interpolate(this._current, a);

  this._current = i(0);

  return function(t) { return pieTop(i(t), rx, ry, ir);  };

}

function arcTweenOuter(a) {

  var i = d3.interpolate(this._current, a);

  this._current = i(0);

  return function(t) { return pieOuter(i(t), rx-.5, ry-.5, h);  };

}

function textTweenX(a) {

  var i = d3.interpolate(this._current, a);

  this._current = i(0);

  return function(t) { return 0.6*rx*Math.cos(0.5*(i(t).startAngle+i(t).endAngle));  };

}

function textTweenY(a) {

  var i = d3.interpolate(this._current, a);

  this._current = i(0);

  return function(t) { return 0.6*rx*Math.sin(0.5*(i(t).startAngle+i(t).endAngle));  };

}

var _data = d3.layout.pie().sort(null).value(function(d) {return d.value;})(data);

d3.select("#"+id).selectAll(".innerSlice").data(_data)

.transition().duration(750).attrTween("d", arcTweenInner);

d3.select("#"+id).selectAll(".topSlice").data(_data)

.transition().duration(750).attrTween("d", arcTweenTop);

d3.select("#"+id).selectAll(".outerSlice").data(_data)

.transition().duration(750).attrTween("d", arcTweenOuter);

d3.select("#"+id).selectAll(".percent").data(_data).transition().duration(750)

.attrTween("x",textTweenX).attrTween("y",textTweenY).text(getPercent);

}

Donut3D.draw=function(id, data, x /*center x*/, y/*center y*/,

rx/*radius x*/, ry/*radius y*/, h/*height*/, ir/*inner radius*/){

var _data = d3.layout.pie().sort(null).value(function(d) {return d.value;})(data);

var slices = d3.select("#"+id).append("g").attr("transform", "translate(" + x + "," + y + ")")

.attr("class", "slices");

slices.selectAll(".innerSlice").data(_data).enter().append("path").attr("class", "innerSlice")

.style("fill", function(d) { return d3.hsl(d.data.color).darker(0.7); })

.attr("d",function(d){ return pieInner(d, rx+0.5,ry+0.5, h, ir);})

.each(function(d){this._current=d;});

slices.selectAll(".topSlice").data(_data).enter().append("path").attr("class", "topSlice")

.style("fill", function(d) { return d.data.color; })

.style("stroke", function(d) { return d.data.color; })

.attr("d",function(d){ return pieTop(d, rx, ry, ir);})

.each(function(d){this._current=d;});

slices.selectAll(".outerSlice").data(_data).enter().append("path").attr("class", "outerSlice")

.style("fill", function(d) { return d3.hsl(d.data.color).darker(0.7); })

.attr("d",function(d){ return pieOuter(d, rx-.5,ry-.5, h);})

.each(function(d){this._current=d;});

slices.selectAll(".percent").data(_data).enter().append("text").attr("class", "percent")

.attr("x",function(d){ return 0.6*rx*Math.cos(0.5*(d.startAngle+d.endAngle));})

.attr("y",function(d){ return 0.6*ry*Math.sin(0.5*(d.startAngle+d.endAngle));})

.text(getPercent).each(function(d){this._current=d;});

}

this.Donut3D = Donut3D;

}();