如何在d3图形中使用json数组

Question

我正在尝试使用此示例http://bl.ocks.org/mbostock/3943967创建d3条形图。在此示例中，他们使用Lee Byron的测试数据生成器。我删除了随机数并放入了硬代码值。正确的图表。任何人都可以告诉您如何删除此数字生成器并将数组添加到图表。

Answer 1

Look at this piece of code:

var n = 4, // number of layers
    m = 25, // number of samples per layer
    stack = d3.layout.stack(),
    layers = stack(d3.range(n).map(function() { return bumpLayer(m, .1); }))

Basically, its a stacked chart so you need to organize your data conveniently:

var data = [
// first group
{
 "index":"0",
 "position":"bottom",
 "num_visitors":"30"
},
{
 "index":"0",
 "position":"middle",
 "num_visitors":"10"
},
{
 "index":"0",
 "position":"top",
 "num_visitors":"15"
},
// second group
{
 "index":"1",
 "position":"bottom",
 "num_visitors":"56"
},
{
 "index":"1",
 "position":"middle",
 "num_visitors":"32"
},
{
 "index":"1",
 "position":"top",
 "num_visitors":"21"
}, ....