D3网格线和刻度值问题

Question

我有一个使用D3制作的堆积区域图表。我的实施面临两个问题。

1）我只想在y轴上显示替代的刻度值。例如，在我的实现中，y轴值为0, 20, 40, 60, 80, 100，依此类推。但我想显示像0, 40, 80, 120这样的值，但也保持相应的网格线。我只是想在不删除y轴网格线的情况下删除替代刻度值。

2）我想格式化y轴，因此它应始终具有上y轴网格线。所以在我的实现中，我希望网格线的值高于180。

＆＃13;

＆＃13;

var margin = {
    top: 20,
    right: 30,
    bottom: 30,
    left: 40
  },
  width = 960 - margin.left - margin.right,
  height = 500 - margin.top - margin.bottom;

var x = d3.time.scale()
  .range([0, width]);

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

var z = d3.scale.category20c();

var xAxis = d3.svg.axis()
  .scale(x)
  .orient("bottom")


var yAxis = d3.svg.axis()
  .scale(y).innerTickSize(-width).outerTickSize(0)
  .orient("left");

var stack = d3.layout.stack()
  .offset("zero")
  .values(function(d) {
    return d.data;
  })
  .x(function(d) {
    return new Date(d[0]);
  })
  .y(function(d) {
    return d[1];
  });



var area = d3.svg.area()
  .interpolate("cardinal")
  .x(function(d) {
    return x(new Date(d[0]));;
  })
  .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 + margin.left + margin.right)
  .attr("height", height + margin.top + margin.bottom)
  .append("g")
  .attr("transform", "translate(" + margin.left + "," + margin.top + ")");


var b = [{
  data: [
    ["2016-01-20T05:31:17.000Z", 95.9, {}],
    ["2016-01-20T05:31:47.000Z", 95.9, {}],
    ["2016-01-20T05:32:17.000Z", 95.4, {}],
    ["2016-01-20T05:32:47.000Z", 96.1, {}],
    ["2016-01-20T05:33:17.000Z", 95.7, {}],
    ["2016-01-20T05:33:47.000Z", 95.9, {}],
    ["2016-01-20T05:34:17.000Z", 95.5, {}],
    ["2016-01-20T05:34:47.000Z", 95.9, {}],
    ["2016-01-20T05:35:17.000Z", 95.8, {}],
    ["2016-01-20T05:35:47.000Z", 95.9, {}],
    ["2016-01-20T05:36:17.000Z", 95.7, {}],
    ["2016-01-20T05:36:47.000Z", 95.7, {}],
    ["2016-01-20T05:37:17.000Z", 95.9, {}],
    ["2016-01-20T05:37:47.000Z", 95.5, {}],
    ["2016-01-20T05:38:17.000Z", 95.4, {}],
    ["2016-01-20T05:38:47.000Z", 95.8, {}],
    ["2016-01-20T05:39:17.000Z", 96.0, {}],
    ["2016-01-20T05:39:47.000Z", 96.1, {}],
    ["2016-01-20T05:40:17.000Z", 95.8, {}],
    ["2016-01-20T05:40:47.000Z", 96.0, {}],
    ["2016-01-20T05:41:17.000Z", 95.9, {}],
    ["2016-01-20T05:41:47.000Z", 94.9, {}],
    ["2016-01-20T05:42:17.000Z", 95.8, {}],
    ["2016-01-20T05:42:47.000Z", 95.9, {}],
    ["2016-01-20T05:43:17.000Z", 95.8, {}],
    ["2016-01-20T05:43:47.000Z", 96.0, {}],
    ["2016-01-20T05:44:17.000Z", 95.7, {}],
    ["2016-01-20T05:44:47.000Z", 96.0, {}],
    ["2016-01-20T05:45:17.000Z", 95.9, {}],
    ["2016-01-20T05:45:47.000Z", 96.0, {}],
    ["2016-01-20T05:46:17.000Z", 95.8, {}],
    ["2016-01-20T05:46:47.000Z", 96.0, {}],
    ["2016-01-20T05:47:17.000Z", 95.7, {}],
    ["2016-01-20T05:47:47.000Z", 96.2, {}],
    ["2016-01-20T05:48:17.000Z", 95.8, {}],
    ["2016-01-20T05:48:47.000Z", 95.9, {}],
    ["2016-01-20T05:49:17.000Z", 95.7, {}],
    ["2016-01-20T05:49:47.000Z", 95.9, {}],
    ["2016-01-20T05:50:18.000Z", 95.7, {}],
    ["2016-01-20T05:50:48.000Z", 95.8, {}],
    ["2016-01-20T05:51:18.000Z", 95.7, {}],
    ["2016-01-20T05:51:48.000Z", 95.9, {}],
    ["2016-01-20T05:52:18.000Z", 95.5, {}],
    ["2016-01-20T05:52:48.000Z", 95.9, {}],
    ["2016-01-20T05:53:18.000Z", 95.8, {}],
    ["2016-01-20T05:53:48.000Z", 95.9, {}],
    ["2016-01-20T05:54:18.000Z", 95.7, {}],
    ["2016-01-20T05:54:48.000Z", 95.9, {}],
    ["2016-01-20T05:55:18.000Z", 95.8, {}],
    ["2016-01-20T05:55:48.000Z", 95.8, {}],
    ["2016-01-20T05:56:18.000Z", 95.6, {}],
    ["2016-01-20T05:56:48.000Z", 95.7, {}],
    ["2016-01-20T05:57:18.000Z", 95.7, {}],
    ["2016-01-20T05:57:48.000Z", 95.8, {}],
    ["2016-01-20T05:58:18.000Z", 95.7, {}],
    ["2016-01-20T05:58:48.000Z", 95.7, {}],
    ["2016-01-20T05:59:18.000Z", 95.6, {}],
    ["2016-01-20T05:59:48.000Z", 95.8, {}],
    ["2016-01-20T06:00:18.000Z", 95.7, {}],
    ["2016-01-20T06:00:48.000Z", 95.7, {}],
    ["2016-01-20T06:01:18.000Z", 95.6, {}],
    ["2016-01-20T06:01:48.000Z", 95.7, {}],
    ["2016-01-20T06:02:18.000Z", 95.8, {}],
    ["2016-01-20T06:02:48.000Z", 95.8, {}],
    ["2016-01-20T06:03:18.000Z", 95.8, {}],
    ["2016-01-20T06:03:48.000Z", 95.8, {}],
    ["2016-01-20T06:04:18.000Z", 95.8, {}],
    ["2016-01-20T06:04:48.000Z", 95.8, {}],
    ["2016-01-20T06:05:18.000Z", 95.7, {}],
    ["2016-01-20T06:05:48.000Z", 95.7, {}]
  ],
  label: "a"
}, {
  data: [
    ["2016-01-20T05:31:17.000Z", 95.9, {}],
    ["2016-01-20T05:31:47.000Z", 95.9, {}],
    ["2016-01-20T05:32:17.000Z", 95.4, {}],
    ["2016-01-20T05:32:47.000Z", 96.1, {}],
    ["2016-01-20T05:33:17.000Z", 95.7, {}],
    ["2016-01-20T05:33:47.000Z", 95.9, {}],
    ["2016-01-20T05:34:17.000Z", 95.5, {}],
    ["2016-01-20T05:34:47.000Z", 95.9, {}],
    ["2016-01-20T05:35:17.000Z", 95.8, {}],
    ["2016-01-20T05:35:47.000Z", 95.9, {}],
    ["2016-01-20T05:36:17.000Z", 95.7, {}],
    ["2016-01-20T05:36:47.000Z", 95.7, {}],
    ["2016-01-20T05:37:17.000Z", 95.9, {}],
    ["2016-01-20T05:37:47.000Z", 95.5, {}],
    ["2016-01-20T05:38:17.000Z", 95.4, {}],
    ["2016-01-20T05:38:47.000Z", 95.8, {}],
    ["2016-01-20T05:39:17.000Z", 96.0, {}],
    ["2016-01-20T05:39:47.000Z", 96.1, {}],
    ["2016-01-20T05:40:17.000Z", 95.8, {}],
    ["2016-01-20T05:40:47.000Z", 96.0, {}],
    ["2016-01-20T05:41:17.000Z", 95.9, {}],
    ["2016-01-20T05:41:47.000Z", 94.9, {}],
    ["2016-01-20T05:42:17.000Z", 95.8, {}],
    ["2016-01-20T05:42:47.000Z", 95.9, {}],
    ["2016-01-20T05:43:17.000Z", 95.8, {}],
    ["2016-01-20T05:43:47.000Z", 96.0, {}],
    ["2016-01-20T05:44:17.000Z", 95.7, {}],
    ["2016-01-20T05:44:47.000Z", 96.0, {}],
    ["2016-01-20T05:45:17.000Z", 95.9, {}],
    ["2016-01-20T05:45:47.000Z", 96.0, {}],
    ["2016-01-20T05:46:17.000Z", 95.8, {}],
    ["2016-01-20T05:46:47.000Z", 96.0, {}],
    ["2016-01-20T05:47:17.000Z", 95.7, {}],
    ["2016-01-20T05:47:47.000Z", 96.2, {}],
    ["2016-01-20T05:48:17.000Z", 95.8, {}],
    ["2016-01-20T05:48:47.000Z", 95.9, {}],
    ["2016-01-20T05:49:17.000Z", 95.7, {}],
    ["2016-01-20T05:49:47.000Z", 95.9, {}],
    ["2016-01-20T05:50:18.000Z", 95.7, {}],
    ["2016-01-20T05:50:48.000Z", 95.8, {}],
    ["2016-01-20T05:51:18.000Z", 95.7, {}],
    ["2016-01-20T05:51:48.000Z", 95.9, {}],
    ["2016-01-20T05:52:18.000Z", 95.5, {}],
    ["2016-01-20T05:52:48.000Z", 95.9, {}],
    ["2016-01-20T05:53:18.000Z", 95.8, {}],
    ["2016-01-20T05:53:48.000Z", 95.9, {}],
    ["2016-01-20T05:54:18.000Z", 95.7, {}],
    ["2016-01-20T05:54:48.000Z", 95.9, {}],
    ["2016-01-20T05:55:18.000Z", 95.8, {}],
    ["2016-01-20T05:55:48.000Z", 95.8, {}],
    ["2016-01-20T05:56:18.000Z", 95.6, {}],
    ["2016-01-20T05:56:48.000Z", 95.7, {}],
    ["2016-01-20T05:57:18.000Z", 95.7, {}],
    ["2016-01-20T05:57:48.000Z", 95.8, {}],
    ["2016-01-20T05:58:18.000Z", 95.7, {}],
    ["2016-01-20T05:58:48.000Z", 95.7, {}],
    ["2016-01-20T05:59:18.000Z", 95.6, {}],
    ["2016-01-20T05:59:48.000Z", 95.8, {}],
    ["2016-01-20T06:00:18.000Z", 95.7, {}],
    ["2016-01-20T06:00:48.000Z", 95.7, {}],
    ["2016-01-20T06:01:18.000Z", 95.6, {}],
    ["2016-01-20T06:01:48.000Z", 95.7, {}],
    ["2016-01-20T06:02:18.000Z", 95.8, {}],
    ["2016-01-20T06:02:48.000Z", 95.8, {}],
    ["2016-01-20T06:03:18.000Z", 95.8, {}],
    ["2016-01-20T06:03:48.000Z", 95.8, {}],
    ["2016-01-20T06:04:18.000Z", 95.8, {}],
    ["2016-01-20T06:04:48.000Z", 95.8, {}],
    ["2016-01-20T06:05:18.000Z", 95.7, {}],
    ["2016-01-20T06:05:48.000Z", 95.7, {}]
  ],
  label: "b"
}]




var layers = stack(b);

var ary = [];
layers.forEach(function(d) {
  ary.push(d.data)
})

x.domain(d3.extent(d3.merge(ary), function(d) {
  return new Date(d[0]);
}));
y.domain([0, d3.max(d3.merge(ary), function(d) {
  return d.y0 + d.y;
})]);


svg.selectAll(".layer")
  .data(layers)
  .enter().append("path")
  .attr("class", "layer")
  .attr("d", function(d) {
    return area(d.data);
  })
  .style("fill", function(d, i) {
    return z(i);
  });

svg.append("g")
  .attr("class", "x axis")
  .attr("transform", "translate(0," + height + ")")
  .call(xAxis);

svg.append("g")
  .attr("class", "y axis")
  .call(yAxis);

＆＃13;

body {
  font: 10px sans-serif;
}
.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

＆＃13;

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>

＆＃13;

＆＃13;

＆＃13;

注意：数据值是动态的，因此y轴刻度值不固定。请帮我找到适用于任何数据的解决方案。

Answer 1

通过设置yAxis。

的参数，可以轻松解决您的要求

1. 可以使用axis.tickValues()覆盖自定义刻度生成器提供的值来指定自定义刻度值。对于您的情况，这意味着致电yAxis.tickValues([0, 40, 80, 120])。要在仍然绘制网格线时隐藏某些刻度值，您可以使用axis.tickFormat() - 根据您的逻辑 - 需要为每个要省略的刻度值返回空字符串。下面的示例将显示每秒的刻度值，但您可以随意实现任何逻辑。

2. 如果你想在图表上方有一个封闭的网格线，你可以使用yAxis.outerTickSize(-width)，它会在比例范围的最小/最大值处添加网格线，就像内部网格线一样。为中间值添加。但请注意，作为副作用，这也会在y轴的下端添加一条网格线，在您的情况下不会受到伤害，因为它与您的x-相同轴。

生成yAxis的代码如下所示：

var yTicks = [40,80,120,160];               // Use whatever values you like.
var yAxis = d3.svg.axis()
  .scale(y)
  .innerTickSize(-width)
  .outerTickSize(-width)                    // Set to -width for upper/lower grid lines
  .tickValues(yTicks)                       // Set custom grid values.
  .tickFormat(function(d) {
    return yTicks.indexOf(d) % 2 ? d : "";  // Custom tickFormat to hide certain tickValues
  })
  .orient("left");

如果您不希望上面的网格线与值“＃39;路径，您可以通过扩展比例域来添加一点填充：

y.domain([0, d3.max(d3.merge(ary), function(d) {
  return d.y0 + d.y;
}) * 1.1]);   // Extending the extent's max value by .1 to allow for padding.

＆＃13;
＆＃13;
var margin = {
    top: 20,
    right: 30,
    bottom: 30,
    left: 40
  },
  width = 960 - margin.left - margin.right,
  height = 500 - margin.top - margin.bottom;

var x = d3.time.scale()
  .range([0, width]);

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

var z = d3.scale.category20c();

var xAxis = d3.svg.axis()
  .scale(x)
  .orient("bottom")

var yTicks = [40,80,120,160];               // Use whatever values you like.
var yAxis = d3.svg.axis()
  .scale(y)
  .innerTickSize(-width)
  .outerTickSize(-width)                    // Set to -width for upper/lower grid lines
  .tickValues(yTicks)                       // Set custom grid values.
  .tickFormat(function(d) {
    return yTicks.indexOf(d) % 2 ? d : "";  // Use a custom tickFormat to hide certain tickValues
  })
  .orient("left");

var stack = d3.layout.stack()
  .offset("zero")
  .values(function(d) {
    return d.data;
  })
  .x(function(d) {
    return new Date(d[0]);
  })
  .y(function(d) {
    return d[1];
  });



var area = d3.svg.area()
  .interpolate("cardinal")
  .x(function(d) {
    return x(new Date(d[0]));;
  })
  .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 + margin.left + margin.right)
  .attr("height", height + margin.top + margin.bottom)
  .append("g")
  .attr("transform", "translate(" + margin.left + "," + margin.top + ")");


var b = [{
  data: [
    ["2016-01-20T05:31:17.000Z", 95.9, {}],
    ["2016-01-20T05:31:47.000Z", 95.9, {}],
    ["2016-01-20T05:32:17.000Z", 95.4, {}],
    ["2016-01-20T05:32:47.000Z", 96.1, {}],
    ["2016-01-20T05:33:17.000Z", 95.7, {}],
    ["2016-01-20T05:33:47.000Z", 95.9, {}],
    ["2016-01-20T05:34:17.000Z", 95.5, {}],
    ["2016-01-20T05:34:47.000Z", 95.9, {}],
    ["2016-01-20T05:35:17.000Z", 95.8, {}],
    ["2016-01-20T05:35:47.000Z", 95.9, {}],
    ["2016-01-20T05:36:17.000Z", 95.7, {}],
    ["2016-01-20T05:36:47.000Z", 95.7, {}],
    ["2016-01-20T05:37:17.000Z", 95.9, {}],
    ["2016-01-20T05:37:47.000Z", 95.5, {}],
    ["2016-01-20T05:38:17.000Z", 95.4, {}],
    ["2016-01-20T05:38:47.000Z", 95.8, {}],
    ["2016-01-20T05:39:17.000Z", 96.0, {}],
    ["2016-01-20T05:39:47.000Z", 96.1, {}],
    ["2016-01-20T05:40:17.000Z", 95.8, {}],
    ["2016-01-20T05:40:47.000Z", 96.0, {}],
    ["2016-01-20T05:41:17.000Z", 95.9, {}],
    ["2016-01-20T05:41:47.000Z", 94.9, {}],
    ["2016-01-20T05:42:17.000Z", 95.8, {}],
    ["2016-01-20T05:42:47.000Z", 95.9, {}],
    ["2016-01-20T05:43:17.000Z", 95.8, {}],
    ["2016-01-20T05:43:47.000Z", 96.0, {}],
    ["2016-01-20T05:44:17.000Z", 95.7, {}],
    ["2016-01-20T05:44:47.000Z", 96.0, {}],
    ["2016-01-20T05:45:17.000Z", 95.9, {}],
    ["2016-01-20T05:45:47.000Z", 96.0, {}],
    ["2016-01-20T05:46:17.000Z", 95.8, {}],
    ["2016-01-20T05:46:47.000Z", 96.0, {}],
    ["2016-01-20T05:47:17.000Z", 95.7, {}],
    ["2016-01-20T05:47:47.000Z", 96.2, {}],
    ["2016-01-20T05:48:17.000Z", 95.8, {}],
    ["2016-01-20T05:48:47.000Z", 95.9, {}],
    ["2016-01-20T05:49:17.000Z", 95.7, {}],
    ["2016-01-20T05:49:47.000Z", 95.9, {}],
    ["2016-01-20T05:50:18.000Z", 95.7, {}],
    ["2016-01-20T05:50:48.000Z", 95.8, {}],
    ["2016-01-20T05:51:18.000Z", 95.7, {}],
    ["2016-01-20T05:51:48.000Z", 95.9, {}],
    ["2016-01-20T05:52:18.000Z", 95.5, {}],
    ["2016-01-20T05:52:48.000Z", 95.9, {}],
    ["2016-01-20T05:53:18.000Z", 95.8, {}],
    ["2016-01-20T05:53:48.000Z", 95.9, {}],
    ["2016-01-20T05:54:18.000Z", 95.7, {}],
    ["2016-01-20T05:54:48.000Z", 95.9, {}],
    ["2016-01-20T05:55:18.000Z", 95.8, {}],
    ["2016-01-20T05:55:48.000Z", 95.8, {}],
    ["2016-01-20T05:56:18.000Z", 95.6, {}],
    ["2016-01-20T05:56:48.000Z", 95.7, {}],
    ["2016-01-20T05:57:18.000Z", 95.7, {}],
    ["2016-01-20T05:57:48.000Z", 95.8, {}],
    ["2016-01-20T05:58:18.000Z", 95.7, {}],
    ["2016-01-20T05:58:48.000Z", 95.7, {}],
    ["2016-01-20T05:59:18.000Z", 95.6, {}],
    ["2016-01-20T05:59:48.000Z", 95.8, {}],
    ["2016-01-20T06:00:18.000Z", 95.7, {}],
    ["2016-01-20T06:00:48.000Z", 95.7, {}],
    ["2016-01-20T06:01:18.000Z", 95.6, {}],
    ["2016-01-20T06:01:48.000Z", 95.7, {}],
    ["2016-01-20T06:02:18.000Z", 95.8, {}],
    ["2016-01-20T06:02:48.000Z", 95.8, {}],
    ["2016-01-20T06:03:18.000Z", 95.8, {}],
    ["2016-01-20T06:03:48.000Z", 95.8, {}],
    ["2016-01-20T06:04:18.000Z", 95.8, {}],
    ["2016-01-20T06:04:48.000Z", 95.8, {}],
    ["2016-01-20T06:05:18.000Z", 95.7, {}],
    ["2016-01-20T06:05:48.000Z", 95.7, {}]
  ],
  label: "a"
}, {
  data: [
    ["2016-01-20T05:31:17.000Z", 95.9, {}],
    ["2016-01-20T05:31:47.000Z", 95.9, {}],
    ["2016-01-20T05:32:17.000Z", 95.4, {}],
    ["2016-01-20T05:32:47.000Z", 96.1, {}],
    ["2016-01-20T05:33:17.000Z", 95.7, {}],
    ["2016-01-20T05:33:47.000Z", 95.9, {}],
    ["2016-01-20T05:34:17.000Z", 95.5, {}],
    ["2016-01-20T05:34:47.000Z", 95.9, {}],
    ["2016-01-20T05:35:17.000Z", 95.8, {}],
    ["2016-01-20T05:35:47.000Z", 95.9, {}],
    ["2016-01-20T05:36:17.000Z", 95.7, {}],
    ["2016-01-20T05:36:47.000Z", 95.7, {}],
    ["2016-01-20T05:37:17.000Z", 95.9, {}],
    ["2016-01-20T05:37:47.000Z", 95.5, {}],
    ["2016-01-20T05:38:17.000Z", 95.4, {}],
    ["2016-01-20T05:38:47.000Z", 95.8, {}],
    ["2016-01-20T05:39:17.000Z", 96.0, {}],
    ["2016-01-20T05:39:47.000Z", 96.1, {}],
    ["2016-01-20T05:40:17.000Z", 95.8, {}],
    ["2016-01-20T05:40:47.000Z", 96.0, {}],
    ["2016-01-20T05:41:17.000Z", 95.9, {}],
    ["2016-01-20T05:41:47.000Z", 94.9, {}],
    ["2016-01-20T05:42:17.000Z", 95.8, {}],
    ["2016-01-20T05:42:47.000Z", 95.9, {}],
    ["2016-01-20T05:43:17.000Z", 95.8, {}],
    ["2016-01-20T05:43:47.000Z", 96.0, {}],
    ["2016-01-20T05:44:17.000Z", 95.7, {}],
    ["2016-01-20T05:44:47.000Z", 96.0, {}],
    ["2016-01-20T05:45:17.000Z", 95.9, {}],
    ["2016-01-20T05:45:47.000Z", 96.0, {}],
    ["2016-01-20T05:46:17.000Z", 95.8, {}],
    ["2016-01-20T05:46:47.000Z", 96.0, {}],
    ["2016-01-20T05:47:17.000Z", 95.7, {}],
    ["2016-01-20T05:47:47.000Z", 96.2, {}],
    ["2016-01-20T05:48:17.000Z", 95.8, {}],
    ["2016-01-20T05:48:47.000Z", 95.9, {}],
    ["2016-01-20T05:49:17.000Z", 95.7, {}],
    ["2016-01-20T05:49:47.000Z", 95.9, {}],
    ["2016-01-20T05:50:18.000Z", 95.7, {}],
    ["2016-01-20T05:50:48.000Z", 95.8, {}],
    ["2016-01-20T05:51:18.000Z", 95.7, {}],
    ["2016-01-20T05:51:48.000Z", 95.9, {}],
    ["2016-01-20T05:52:18.000Z", 95.5, {}],
    ["2016-01-20T05:52:48.000Z", 95.9, {}],
    ["2016-01-20T05:53:18.000Z", 95.8, {}],
    ["2016-01-20T05:53:48.000Z", 95.9, {}],
    ["2016-01-20T05:54:18.000Z", 95.7, {}],
    ["2016-01-20T05:54:48.000Z", 95.9, {}],
    ["2016-01-20T05:55:18.000Z", 95.8, {}],
    ["2016-01-20T05:55:48.000Z", 95.8, {}],
    ["2016-01-20T05:56:18.000Z", 95.6, {}],
    ["2016-01-20T05:56:48.000Z", 95.7, {}],
    ["2016-01-20T05:57:18.000Z", 95.7, {}],
    ["2016-01-20T05:57:48.000Z", 95.8, {}],
    ["2016-01-20T05:58:18.000Z", 95.7, {}],
    ["2016-01-20T05:58:48.000Z", 95.7, {}],
    ["2016-01-20T05:59:18.000Z", 95.6, {}],
    ["2016-01-20T05:59:48.000Z", 95.8, {}],
    ["2016-01-20T06:00:18.000Z", 95.7, {}],
    ["2016-01-20T06:00:48.000Z", 95.7, {}],
    ["2016-01-20T06:01:18.000Z", 95.6, {}],
    ["2016-01-20T06:01:48.000Z", 95.7, {}],
    ["2016-01-20T06:02:18.000Z", 95.8, {}],
    ["2016-01-20T06:02:48.000Z", 95.8, {}],
    ["2016-01-20T06:03:18.000Z", 95.8, {}],
    ["2016-01-20T06:03:48.000Z", 95.8, {}],
    ["2016-01-20T06:04:18.000Z", 95.8, {}],
    ["2016-01-20T06:04:48.000Z", 95.8, {}],
    ["2016-01-20T06:05:18.000Z", 95.7, {}],
    ["2016-01-20T06:05:48.000Z", 95.7, {}]
  ],
  label: "b"
}]




var layers = stack(b);

var ary = [];
layers.forEach(function(d) {
  ary.push(d.data)
})

x.domain(d3.extent(d3.merge(ary), function(d) {
  return new Date(d[0]);
}));
y.domain([0, d3.max(d3.merge(ary), function(d) {
  return d.y0 + d.y;
}) * 1.1]);   // Extending the extent's max value by .1 to allow for padding.

svg.selectAll(".layer")
  .data(layers)
  .enter().append("path")
  .attr("class", "layer")
  .attr("d", function(d) {
    return area(d.data);
  })
  .style("fill", function(d, i) {
    return z(i);
  });

svg.append("g")
  .attr("class", "x axis")
  .attr("transform", "translate(0," + height + ")")
  .call(xAxis);

svg.append("g")
  .attr("class", "y axis")
  .call(yAxis);
＆＃13;
body {
  font: 10px sans-serif;
}
.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}
＆＃13;
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>
＆＃13;
＆＃13;
＆＃13;

Answer 2

要制作刻度值，请执行以下操作：

var max = y.domain()[1];
var values = [];
for(var j =0; j <=max; j=j+20){
    values.push(j)
}
values.push(max)

yAxis.tickValues(values);

隐藏备用网格文本：

var last = svg.selectAll(".y .tick text")[0].length;  

svg.selectAll(".y .tick text")[0].forEach(function(d, i){
  if (i==last-1){
    return;//for showing last tick
  }
  if(i%2==0)
    d3.select(d).style("display", "none");//for showing alternate ticks
});

工作代码here