D3.js是一個JavaScript庫，它可(kě)以通過數據來操作(zuò)文(wén)檔。D3可(kě)以通過使用(yòng)HTML、SVG和CSS把數據鮮活形象地展現出來。D3嚴格遵循Web标準，因而可(kě)以讓你的程序輕松兼容現代主流浏覽器并避免對特定框架的依賴。同時，它提供了強大的可(kě)視化組件，可(kě)以讓使用(yòng)者以數據驅動的方式去操作(zuò)DOM。（來自：維基百科(kē)D3.js詞條）

!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;

}();