我是d3.js的新手，但是我发现很难创建分组条形图，但是我尝试了一些似乎不合适的方法。我想在x轴上停留数月，在y轴上记录火星和木星的数量。像dis Link这样的东西。
var svg = d3.select("svg"),
margin = {top: 20, right: 20, bottom: 30, left: 40},
width = +svg.attr("width") - margin.left - margin.right, height = +svg.attr("height") - margin.top - margin.bottom;
var x = d3.scaleBand().rangeRound([0,
width]).padding(0.1),
y = d3.scaleLinear().rangeRound([height, 0]);
var g = svg.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
var data = [
{"Group":"Mars","count":10,"months":"June"},
{"Group":"Jupiter","count":50,"months":"June"},
{"Group":"Mars","count":70,"months":"July"},
{"Group":"Jupiter","count":60,"months":"July"}];
var ymaxdomain=d3.max(d,function(d){return d.count;});
x.domain(d.map(function(d) {return d.months}));
y.domain([0,ymaxdomain]);
var x1=d3.scaleBand().rangeRound([0, x.bandwidth()]);
x1.domain(d.map(function(d) {return d.months;}));
g.selectAll(".bar")
.data(data)
.enter().append("rect")
.attr("x", function(d,i) …