D3.js 流图示例 - 生成正确的面积函数值答案

【问题标题】：D3.js streamgraph example - generating correct area function valuesD3.js 流图示例 - 生成正确的面积函数值
【发布时间】：2013-03-30 16:23:54
【问题描述】：

我是 d3js 的新手，并试图从这里 http://bl.ocks.org/mbostock/4060954 调整流图示例：

...使用我自己的数据来跟踪来自不同地方（在线、留言簿、博物馆）的艺术展览的参观者。我已经取得了一些进展，我认为我的数据格式正确，但是我得到了一些非常不稳定的最终 y 值，而我的示例没有显示任何内容。

我的数据以 csv 开头：

index,date,venue,num_visitors
0,4/6/2013,online,3844
0,4/6/2013,museum,789
0,4/6/2013,guestbook,20
1,4/7/2013,online,217
1,4/7/2013,museum,718
1,4/7/2013,guestbook,20

然后我嵌套它以按场地（在线、博物馆、留言簿）组织成 3 层/流：

layer0 = [
  {
    "key": "online",
    "values": [
      { "x": 0, "y":  3844},
      { "x": 1, "y": 217}
      etc

    ]
  },
  {  
    "key": "museum",
    "values": [
      { "x": 0, "y":  789},
      { "x": 1, "y": 718}
      etc
    ]
  }
];

生成页面时，y 值始终为 800，svg 路径对象的宽度为 1400 像素，高度为 0。我不确定这是否是我如何将输入域缩放到输出范围的问题，或者是否是面积函数生成 y 值的问题。以下是其中一条生成路径的点值显示示例：

d="M0,800L17.72151898734177,800L35.44303797468354,800L53.164556962025316,800L70.88607594936708, etc"

这是我的完整页面 - 非常感谢一些指导，因为我觉得我在这里遗漏了一些简单的东西。

<!DOCTYPE html>
<meta charset="utf-8">
<title>Streamgraph</title>
<style>

body {
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  margin: 0;
  position: relative;
  width: 1400px;
}

button {
  position: absolute;
  right: 10px;
  top: 10px;
}

</style>
<button onclick="transition()">Update</button>
<script src="d3.js"></script>
<script>

var format = d3.time.format("%m/%d/%Y");

d3.csv("streamdata.csv", function(error, data) {
        data.forEach(function(d) {
            d.date = format.parse(d.date);
            d.y = d.num_visitors;
            d.x = d.index;

        });
        window.data = data;

        drawVisitorStats();
});

function drawVisitorStats(){
    var nest = d3.nest()
           .key(function(d){ return d.venue});
    var n = window.data.length, // number of layers, online, guestbook & museum

        stack = d3.layout.stack().offset("wiggle").offset("zero")
          .values(function(d) { return d.values; }),

        //group data by venue
        layers0 = stack(nest.entries(data)),
        layers1 = stack(nest.entries(data));

    var m = layers0[0].values.length; // number of samples per layer

    var yDomain = d3.max(layers0.concat(layers1), function(layer) { 
        return d3.max(layer, 
            function(d) { 
              return d.y0 + d.y; 
            }); 
    });

    var width = 1400,
        height = 800;

    var x = d3.scale.linear()
    .domain([0, m - 1])
    .range([0, width]);

    var y = d3.scale.linear()
    .domain([0, yDomain])
    .range([height, 0]);

    var color = d3.scale.linear()
        .range(["#ff0c00", "#ffc000"]);

    var area = d3.svg.area()
      .x(
        function(d) { 
          return x(d.x); 
        })
        .y0(function(d) { 
          return y(d.y0); 
        })
        .y1(function(d) { 
          return y(d.y0 + d.y); 
        }); 

    var svg = d3.select("body").append("svg")
        .attr("width", width)
        .attr("height", height);

    svg.selectAll("path")
        .data(layers0)
      .enter().append("path")
        .attr("d", function(d) { return area(d.values); })
        .style("fill", function() { return color(Math.random()); });
}
function transition() {
  d3.selectAll("path")
      .data(function() {
        var d = layers1;
        layers1 = layers0;
        return layers0 = d;
      })
    .transition()
      .duration(2500)
      .attr("d", area);
}



</script>

这是数据 csv 文件

index,date,venue,num_visitors
0,4/6/2013,online,3844
0,4/6/2013,museum,789
0,4/6/2013,guestbook,20
1,4/7/2013,online,217
1,4/7/2013,museum,718
1,4/7/2013,guestbook,20
2,4/8/2013,online,203
2,4/8/2013,museum,741
2,4/8/2013,guestbook,6
3,4/9/2013,online,1445
3,4/9/2013,museum,874
3,4/9/2013,guestbook,7
4,4/10/2013,online,3098
4,4/10/2013,museum,755
4,4/10/2013,guestbook,3
5,4/11/2013,online,744
5,4/11/2013,museum,368
5,4/11/2013,guestbook,6
6,4/12/2013,online,1342
6,4/12/2013,museum,826
6,4/12/2013,guestbook,17
7,4/13/2013,online,694
7,4/13/2013,museum,826
7,4/13/2013,guestbook,17
8,4/14/2013,online,213
8,4/14/2013,museum,261
8,4/14/2013,guestbook,7
9,4/15/2013,online,3215
9,4/15/2013,museum,776
9,4/15/2013,guestbook,14
10,4/16/2013,online,2663
10,4/16/2013,museum,331
10,4/16/2013,guestbook,12
11,4/17/2013,online,172
11,4/17/2013,museum,633
11,4/17/2013,guestbook,10
12,4/18/2013,online,4516
12,4/18/2013,museum,543
12,4/18/2013,guestbook,5
13,4/19/2013,online,988
13,4/19/2013,museum,792
13,4/19/2013,guestbook,19
14,4/20/2013,online,2556
14,4/20/2013,museum,663
14,4/20/2013,guestbook,0
15,4/21/2013,online,2814
15,4/21/2013,museum,449
15,4/21/2013,guestbook,18
16,4/22/2013,online,596
16,4/22/2013,museum,445
16,4/22/2013,guestbook,15
17,4/23/2013,online,4790
17,4/23/2013,museum,217
17,4/23/2013,guestbook,5
18,4/24/2013,online,733
18,4/24/2013,museum,655
18,4/24/2013,guestbook,12
19,4/25/2013,online,362
19,4/25/2013,museum,321
19,4/25/2013,guestbook,20
20,4/26/2013,online,637
20,4/26/2013,museum,420
20,4/26/2013,guestbook,3
21,4/27/2013,online,2916
21,4/27/2013,museum,910
21,4/27/2013,guestbook,6
22,4/28/2013,online,1097
22,4/28/2013,museum,468
22,4/28/2013,guestbook,0
23,4/29/2013,online,796
23,4/29/2013,museum,687
23,4/29/2013,guestbook,9
24,4/30/2013,online,821
24,4/30/2013,museum,951
24,4/30/2013,guestbook,12
25,5/1/2013,online,2466
25,5/1/2013,museum,810
25,5/1/2013,guestbook,6
26,5/2/2013,online,1005
26,5/2/2013,museum,291
26,5/2/2013,guestbook,19
27,5/3/2013,online,1243
27,5/3/2013,museum,446
27,5/3/2013,guestbook,5
28,5/4/2013,online,4623
28,5/4/2013,museum,538
28,5/4/2013,guestbook,0
29,5/5/2013,online,547
29,5/5/2013,museum,457
29,5/5/2013,guestbook,11
30,5/6/2013,online,4132
30,5/6/2013,museum,407
30,5/6/2013,guestbook,8
31,5/7/2013,online,3083
31,5/7/2013,museum,741
31,5/7/2013,guestbook,9
32,5/8/2013,online,2854
32,5/8/2013,museum,516
32,5/8/2013,guestbook,1
33,5/9/2013,online,2122
33,5/9/2013,museum,932
33,5/9/2013,guestbook,14
34,5/10/2013,online,587
34,5/10/2013,museum,701
34,5/10/2013,guestbook,0
35,5/11/2013,online,698
35,5/11/2013,museum,887
35,5/11/2013,guestbook,18
36,5/12/2013,online,3538
36,5/12/2013,museum,223
36,5/12/2013,guestbook,4
37,5/13/2013,online,2413
37,5/13/2013,museum,799
37,5/13/2013,guestbook,13
38,5/14/2013,online,3581
38,5/14/2013,museum,744
38,5/14/2013,guestbook,7
39,5/15/2013,online,1750
39,5/15/2013,museum,845
39,5/15/2013,guestbook,17
40,5/16/2013,online,3025
40,5/16/2013,museum,630
40,5/16/2013,guestbook,10
41,5/17/2013,online,2038
41,5/17/2013,museum,342
41,5/17/2013,guestbook,7
42,5/18/2013,online,148
42,5/18/2013,museum,447
42,5/18/2013,guestbook,20
43,5/19/2013,online,886
43,5/19/2013,museum,755
43,5/19/2013,guestbook,20
44,5/20/2013,online,1168
44,5/20/2013,museum,305
44,5/20/2013,guestbook,10
45,5/21/2013,online,190
45,5/21/2013,museum,378
45,5/21/2013,guestbook,11
46,5/22/2013,online,1416
46,5/22/2013,museum,276
46,5/22/2013,guestbook,13
47,5/23/2013,online,1753
47,5/23/2013,museum,380
47,5/23/2013,guestbook,7
48,5/24/2013,online,2573
48,5/24/2013,museum,221
48,5/24/2013,guestbook,17
49,5/25/2013,online,2425
49,5/25/2013,museum,610
49,5/25/2013,guestbook,11
50,5/26/2013,online,3359
50,5/26/2013,museum,492
50,5/26/2013,guestbook,1
51,5/27/2013,online,1853
51,5/27/2013,museum,873
51,5/27/2013,guestbook,4
52,5/28/2013,online,4106
52,5/28/2013,museum,543
52,5/28/2013,guestbook,7
53,5/29/2013,online,591
53,5/29/2013,museum,894
53,5/29/2013,guestbook,11
54,5/30/2013,online,2938
54,5/30/2013,museum,565
54,5/30/2013,guestbook,4
55,5/31/2013,online,2237
55,5/31/2013,museum,313
55,5/31/2013,guestbook,4
56,6/1/2013,online,3754
56,6/1/2013,museum,622
56,6/1/2013,guestbook,10
57,6/2/2013,online,1529
57,6/2/2013,museum,309
57,6/2/2013,guestbook,2
58,6/3/2013,online,1482
58,6/3/2013,museum,636
58,6/3/2013,guestbook,8
59,6/4/2013,online,1607
59,6/4/2013,museum,655
59,6/4/2013,guestbook,8
60,6/5/2013,online,364
60,6/5/2013,museum,485
60,6/5/2013,guestbook,0
61,6/6/2013,online,555
61,6/6/2013,museum,219
61,6/6/2013,guestbook,3
62,6/7/2013,online,4209
62,6/7/2013,museum,674
62,6/7/2013,guestbook,18
63,6/8/2013,online,4767
63,6/8/2013,museum,824
63,6/8/2013,guestbook,11
64,6/9/2013,online,4788
64,6/9/2013,museum,877
64,6/9/2013,guestbook,2
65,6/10/2013,online,295
65,6/10/2013,museum,873
65,6/10/2013,guestbook,14
66,6/11/2013,online,2057
66,6/11/2013,museum,559
66,6/11/2013,guestbook,13
67,6/12/2013,online,3199
67,6/12/2013,museum,592
67,6/12/2013,guestbook,15
68,6/13/2013,online,2453
68,6/13/2013,museum,907
68,6/13/2013,guestbook,12
69,6/14/2013,online,3688
69,6/14/2013,museum,267
69,6/14/2013,guestbook,12
70,6/15/2013,online,352
70,6/15/2013,museum,389
70,6/15/2013,guestbook,15
71,6/16/2013,online,1583
71,6/16/2013,museum,304
71,6/16/2013,guestbook,7
72,6/17/2013,online,4202
72,6/17/2013,museum,438
72,6/17/2013,guestbook,3
73,6/18/2013,online,2652
73,6/18/2013,museum,392
73,6/18/2013,guestbook,1
74,6/19/2013,online,3988
74,6/19/2013,museum,764
74,6/19/2013,guestbook,17
75,6/20/2013,online,3025
75,6/20/2013,museum,663
75,6/20/2013,guestbook,18
76,6/21/2013,online,4057
76,6/21/2013,museum,266
76,6/21/2013,guestbook,9
77,6/22/2013,online,4853
77,6/22/2013,museum,614
77,6/22/2013,guestbook,15
78,6/23/2013,online,1334
78,6/23/2013,museum,745
78,6/23/2013,guestbook,6
79,6/24/2013,online,4729
79,6/24/2013,museum,506
79,6/24/2013,guestbook,8

谢谢！

【问题讨论】：

标签： javascript d3.js area stream-graph

【解决方案1】：

在您的yDomain 定义中，您需要返回每个图层值的最大值，因为每个图层都是一个地图 - 它既有一个键，也有一个值数组，而不仅仅是一个平面数字数组。

var yDomain = d3.max(layers0.concat(layers1), function(layer) { 
    return d3.max(layer.values, //Used to be layer
        function(d) { 
          return d.y0 + d.y; 
        }); 
});

此外，对于您的堆栈定义，您需要删除第二个偏移调用。它否定了“摆动”一个，因此您将获得一个正常的堆叠图而不是流图。

stack = d3.layout.stack().offset("wiggle")  // Used to have .offset("zero") here
      .values(function(d) { return d.values; })

以下是两个都更改的示例：http://jsfiddle.net/G6dTy/3/。留言簿的数字很小，与其他两个值相比相形见绌。

看一下Stacked area chart 示例可能会有所帮助

【讨论】：

【解决方案2】：

谢谢迷你！那非常有帮助。我意识到的另一件事是，我没有将 x & y 值解析为数字，而是将它们作为字符串读取，并使点计算变得疯狂。因此，当它遍历 CSV 文件的行时，它需要使用 parseInt：

data.forEach(function(d) {
        d.date = format.parse(d.date);
        d.y = parseInt(d.num_visitors);
        d.x = parseInt(d.index);

    });

这是我更新的文件，以防将来有人想以此作为示例。

HTML

<!DOCTYPE html>
<meta charset="utf-8">
<title>Streamgraph</title>
<script type="text/javascript" charset="utf-8" src="http://code.jquery.com/jquery-1.8.3.min.js"></script>
<script src="bootstrap/js/bootstrap.min.js"></script>
<link href="bootstrap/css/bootstrap.min.css" rel="stylesheet">
<style>

body {
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  margin: 0;
  position: relative;
  width: 1400px;
  background-color: #053749;
}

button {
  position: absolute;
  right: 10px;
  top: 10px;
}
svg{
  margin-top: 450px;
}

</style>
<script src="d3.js"></script>
<body>
  <div id="layerTitle"></div>
</body>
<script>


var format = d3.time.format("%m/%d/%Y");

d3.csv("streamdata.csv", function(error, data) {
        data.forEach(function(d) {
            d.date = format.parse(d.date);
            d.y = parseInt(d.num_visitors) + 1;
            d.x = parseInt(d.index);

        });
        window.data = data;

        drawVisitorStats();
        //$('path').tooltip('{container:layerTitle}');
        $("path").tooltip({
            'container': 'body',
            'placement': 'bottom'
        });


});

function drawVisitorStats(){
    var nest = d3.nest()
           .key(function(d){ return d.venue});
    var n = window.data.length, // number of layers, online, guestbook & museum

    stack = d3.layout.stack().offset("wiggle")
          .values(function(d) { return d.values; });

    //group data by venue
    layers0 = stack(nest.entries(data));

    var m = layers0[0].values.length; // number of samples per layer

    var allValues = layers0[0].values.concat(layers0[1].values).concat(layers0[2].values);

    var yDomain = d3.max(allValues, function(d) { 
      return d.y0 + d.y; 
    });

    var width = 1400,
        height = 200;

    var x = d3.scale.linear()
      .domain([0, m - 1])
      .range([0, width]);

    var y = d3.scale.linear()
    .domain([1, yDomain])
    .range([height, 0]);

    var color = d3.scale.linear()
        .range(["#053749", "#6bb9d6"]);

    var area = d3.svg.area()
      .x(
        function(d) { 
          return x(d.x); 
        })
        .y0(function(d) {          
          return y(d.y0); 
        })
        .y1(function(d) { 
          return y(d.y0 + d.y); 
        })
        .interpolate("cardinal")
        .tension(0.6); 

    var svg = d3.select("body").append("svg")
        .attr("width", width)
        .attr("height", height);

    svg.selectAll("path")
        .data(layers0)
      .enter().append("path")
        .attr("d", function(d) { return area(d.values); })
        .attr("id", function(d) { 
          return d.key;
        })
        .attr("title", function(d) { 
          return "visitors from " + d.key;
        })
        .style("fill", function() { return color(Math.random()); });
}

</script>
</html>

数据文件

index,date,venue,num_visitors
0,4/8/2013,online,1721
0,4/8/2013,museum,826
0,4/8/2013,guestbook,333
1,4/9/2013,online,1377
1,4/9/2013,museum,840
1,4/9/2013,guestbook,61
2,4/10/2013,online,1849
2,4/10/2013,museum,539
2,4/10/2013,guestbook,191
3,4/11/2013,online,1205
3,4/11/2013,museum,810
3,4/11/2013,guestbook,65
4,4/12/2013,online,1960
4,4/12/2013,museum,957
4,4/12/2013,guestbook,221
5,4/13/2013,online,1215
5,4/13/2013,museum,658
5,4/13/2013,guestbook,384
6,4/14/2013,online,1565
6,4/14/2013,museum,621
6,4/14/2013,guestbook,94
7,4/15/2013,online,1678
7,4/15/2013,museum,710
7,4/15/2013,guestbook,35
8,4/16/2013,online,1267
8,4/16/2013,museum,964
8,4/16/2013,guestbook,8
9,4/17/2013,online,1781
9,4/17/2013,museum,896
9,4/17/2013,guestbook,238
10,4/18/2013,online,1185
10,4/18/2013,museum,712
10,4/18/2013,guestbook,318
11,4/19/2013,online,1097
11,4/19/2013,museum,753
11,4/19/2013,guestbook,132
12,4/20/2013,online,1053
12,4/20/2013,museum,927
12,4/20/2013,guestbook,399
13,4/21/2013,online,1738
13,4/21/2013,museum,653
13,4/21/2013,guestbook,78
14,4/22/2013,online,1491
14,4/22/2013,museum,568
14,4/22/2013,guestbook,72
15,4/23/2013,online,1403
15,4/23/2013,museum,997
15,4/23/2013,guestbook,184
16,4/24/2013,online,1335
16,4/24/2013,museum,987
16,4/24/2013,guestbook,26
17,4/25/2013,online,1964
17,4/25/2013,museum,753
17,4/25/2013,guestbook,239
18,4/26/2013,online,1260
18,4/26/2013,museum,815
18,4/26/2013,guestbook,249
19,4/27/2013,online,1404
19,4/27/2013,museum,817
19,4/27/2013,guestbook,360
20,4/28/2013,online,1790
20,4/28/2013,museum,840
20,4/28/2013,guestbook,163
21,4/29/2013,online,1698
21,4/29/2013,museum,700
21,4/29/2013,guestbook,129
22,4/30/2013,online,1479
22,4/30/2013,museum,921
22,4/30/2013,guestbook,347
23,5/1/2013,online,1093
23,5/1/2013,museum,720
23,5/1/2013,guestbook,278
24,5/2/2013,online,1148
24,5/2/2013,museum,655
24,5/2/2013,guestbook,162
25,5/3/2013,online,1521
25,5/3/2013,museum,806
25,5/3/2013,guestbook,267
26,5/4/2013,online,1365
26,5/4/2013,museum,662
26,5/4/2013,guestbook,232
27,5/5/2013,online,1809
27,5/5/2013,museum,659
27,5/5/2013,guestbook,398
28,5/6/2013,online,1078
28,5/6/2013,museum,999
28,5/6/2013,guestbook,51
29,5/7/2013,online,1477
29,5/7/2013,museum,512
29,5/7/2013,guestbook,385

【讨论】：

【解决方案3】：

请注意，有一个后续问题 here 基于相同的 CSV 数据但尝试使用转换。同样，错误与“区域”有关，但在转换函数内。

【讨论】：

这可以作为评论而不是答案发布。
点击“添加评论”链接告诉我我必须有 50 声望才能发表评论。
我知道，在 Stackoverflow 上做新手很难。