分组条形图 D3.js 条内的文本答案

【问题标题】：Text inside Bar of the Grouped Bar Chart D3.js分组条形图 D3.js 条内的文本
【发布时间】：2021-08-21 13:32:17
【问题描述】：

我确实参考了这个https://bl.ocks.org/mbostock/3887051 并做了一些修改制作了这个条形图。尝试在基本计数的栏中添加文本。例如上游是50，所以50应该在酒吧里。

为此，我尝试了D3.js grouped bar chart text on bars、How to label each bar from a grouped bar chart?，但无法做到。

var data = [{
    "title": "abc",
    "Upstream": 50,
    "Downstream": 15
  },
  {
    "title": "xyz",
    "Upstream": 107,
    "Downstream": 12
  }
]
var margin = {
    top: 20,
    right: 20,
    bottom: 30,
    left: 40
  },
  width = 600 - margin.left - margin.right,
  height = 500 - margin.top - margin.bottom;

var x0 = d3.scale.ordinal()
  .rangeRoundBands([0, width], .1);

var x1 = d3.scale.ordinal();

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

var color = d3.scale.ordinal()
  .range(["green", "red"]);

var xAxis = d3.svg.axis()
  .scale(x0)
  .orient("bottom");

var yAxis = d3.svg.axis()
  .scale(y)
  .orient("left")
  .tickFormat(d3.format(".2s"));

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 ageNames = d3.keys(data[0]).filter(function(key) {
  return key !== "title";
});

data.forEach(function(d) {
  d.ages = ageNames.map(function(name) {
    return {
      name: name,
      value: +d[name]
    };
  });
});

x0.domain(data.map(function(d) {
  return d.title;
}));
x1.domain(ageNames).rangeRoundBands([0, x0.rangeBand()]);
y.domain([0, d3.max(data, function(d) {
  return d3.max(d.ages, function(d) {
    return d.value;
  });
})]);

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

// Y-axis
svg.append("g")
  .attr("class", "y axis")
  .call(yAxis)
  .append("text")
  .attr("transform", "rotate(-90)")
  .attr("y", 6)
  .attr("dy", ".71em")
  .style("text-anchor", "end")
  .text("Number of Regulated Genes");

// Bars
var title = svg.selectAll(".title")
  .data(data)
  .enter().append("g")
  .attr("class", "title")
  .attr("transform", function(d) {
    return "translate(" + x0(d.title) + ",0)";
  });

title.selectAll("rect")
  .data(function(d) {
    return d.ages;
  })
  .enter().append("rect")
  .attr("width", x1.rangeBand())
  .attr("x", function(d) {
    return x1(d.name);
  })
  .attr("y", function(d) {
    return y(d.value);
  })
  .attr("height", function(d) {
    return height - y(d.value);
  })
  .style("fill", function(d) {
    return color(d.name);
  });

// Legends which is in right side
var legend = svg.selectAll(".legend")
  .data(ageNames.slice().reverse())
  .enter().append("g")
  .attr("class", "legend")
  .attr("transform", function(d, i) {
    return "translate(0," + i * 20 + ")";
  });

legend.append("rect")
  .attr("x", width - 18)
  .attr("width", 18)
  .attr("height", 18)
  .style("fill", color);

legend.append("text")
  .attr("x", width - 24)
  .attr("y", 9)
  .attr("dy", ".35em")
  .style("text-anchor", "end")
  .text(function(d) {
    return d;
  });

body {
  font: 12px sans-serif;
}

.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

.bar {
  fill: steelblue;
}

.x.axis path {
  display: none;
}

<script src="https://d3js.org/d3.v3.min.js"></script>
<body></body>

【问题讨论】：

标签： javascript svg d3.js

【解决方案1】：

在<rect>之后追加<text>，如sn-p所示：

var data = [{
    "title": "abc",
    "Upstream": 50,
    "Downstream": 15
  },
  {
    "title": "xyz",
    "Upstream": 107,
    "Downstream": 12
  }
]
var margin = {
    top: 20,
    right: 20,
    bottom: 30,
    left: 40
  },
  width = 600 - margin.left - margin.right,
  height = 500 - margin.top - margin.bottom;

var x0 = d3.scale.ordinal()
  .rangeRoundBands([0, width], .1);

var x1 = d3.scale.ordinal();

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

var color = d3.scale.ordinal()
  .range(["green", "red"]);

var xAxis = d3.svg.axis()
  .scale(x0)
  .orient("bottom");

var yAxis = d3.svg.axis()
  .scale(y)
  .orient("left")
  .tickFormat(d3.format(".2s"));

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 ageNames = d3.keys(data[0]).filter(function(key) {
  return key !== "title";
});

data.forEach(function(d) {
  d.ages = ageNames.map(function(name) {
    return {
      name: name,
      value: +d[name]
    };
  });
});

x0.domain(data.map(function(d) {
  return d.title;
}));
x1.domain(ageNames).rangeRoundBands([0, x0.rangeBand()]);
y.domain([0, d3.max(data, function(d) {
  return d3.max(d.ages, function(d) {
    return d.value;
  });
})]);

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

// Y-axis
svg.append("g")
  .attr("class", "y axis")
  .call(yAxis)
  .append("text")
  .attr("transform", "rotate(-90)")
  .attr("y", 6)
  .attr("dy", ".71em")
  .style("text-anchor", "end")
  .text("Number of Regulated Genes");

// Bars
var title = svg.selectAll(".title")
  .data(data)
  .enter().append("g")
  .attr("class", "title")
  .attr("transform", function(d) {
    return "translate(" + x0(d.title) + ",0)";
  });

title.selectAll("rect")
  .data(function(d) {
    return d.ages;
  })
  .enter().append("rect")
  .attr("width", x1.rangeBand())
  .attr("x", function(d) {
    return x1(d.name);
  })
  .attr("y", function(d) {
    return y(d.value);
  })
  .attr("height", function(d) {
    return height - y(d.value);
  })
  .style("fill", function(d) {
    return color(d.name);
  });

title.selectAll("text")
  .data(function(d) {
    return d.ages;
  })
  .enter()
  .append('text')
  .classed('bar-label', true)
  .text(d => d.value)
  .attr("x", function(d) {
    return x1(d.name) + x1.rangeBand() / 2;
  })
  .attr("y", function(d) {
    return y(d.value) + 4;
  })
  .attr('text-anchor', 'middle')
  .attr('alignment-baseline', 'hanging')


// Legends which is in right side
var legend = svg.selectAll(".legend")
  .data(ageNames.slice().reverse())
  .enter().append("g")
  .attr("class", "legend")
  .attr("transform", function(d, i) {
    return "translate(0," + i * 20 + ")";
  });

legend.append("rect")
  .attr("x", width - 18)
  .attr("width", 18)
  .attr("height", 18)
  .style("fill", color);

legend.append("text")
  .attr("x", width - 24)
  .attr("y", 9)
  .attr("dy", ".35em")
  .style("text-anchor", "end")
  .text(function(d) {
    return d;
  });

body {
  font: 12px sans-serif;
}

.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

.bar {
  fill: steelblue;
}

.x.axis path {
  display: none;
}

.bar-label {
  fill: white;
}

<script src="https://d3js.org/d3.v3.min.js"></script>
<body></body>

【讨论】：