mbostock/.block

## .block
license: gpl-3.0
redirect: https://observablehq.com/@d3/inline-labels

## README.md

      
    Raw
  

              README.md
            
          
    This example shows how to implement Ann K. Emery’s technique of placings labels directly on top of a line in D3 4.0 Alpha.
To construct the multi-series line chart, the data is first transformed into separate arrays for each series. (The series names are automatically derived from the columns in the TSV file, thanks to a new dsv.parse feature.)
var series = data.columns.slice(1).map(function(key) {
  return data.map(function(d) {
    return {
      key: key,
      date: d.date,
      value: d[key]
    };
  });
});
A label is rendered for each point in each series. Beneath this label, a white rectangle is added, whose size and position is computed automatically using element.getBBox plus a little bit of padding. The resulting label is thus legible. The last label for each series gets an additional tspan to show the series name.

  
## data.tsv

          
            date
            Apples
            Bananas

            
              2009
              130
              40

            
              2010
              137
              58

            
              2011
              166
              97

            
              2012
              154
              117

            
              2013
              179
              98

            
              2014
              187
              120

            
              2015
              189
              84

## index.html
<!DOCTYPE html>
<meta charset="utf-8">
<style>

text {
  font: 10px sans-serif;
}

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

.line {
  fill: none;
  stroke-width: 1.5px;
}

.label {
  text-anchor: middle;
}

.label rect {
  fill: white;
}

.label-key {
  font-weight: bold;
}

</style>
<svg width="960" height="500"></svg>
<script src="//d3js.org/d3.v4.0.0-alpha.9.min.js"></script>
<script>

var parseTime = d3.timeParse("%Y");

var svg = d3.select("svg");

var margin = {top: 30, right: 50, bottom: 30, left: 30},
    width = +svg.attr("width") - margin.left - margin.right,
    height = +svg.attr("height") - margin.top - margin.bottom,
    labelPadding = 3;

var g = svg.append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

d3.requestTsv("data.tsv", function(d) {
  d.date = parseTime(d.date);
  for (var k in d) if (k !== "date") d[k] = +d[k];
  return d;
}, function(error, data) {
  if (error) throw error;

  var series = data.columns.slice(1).map(function(key) {
    return data.map(function(d) {
      return {
        key: key,
        date: d.date,
        value: d[key]
      };
    });
  });

  var x = d3.scaleTime()
      .domain([data[0].date, data[data.length - 1].date])
      .range([0, width]);

  var y = d3.scaleLinear()
      .domain([0, d3.max(series, function(s) { return d3.max(s, function(d) { return d.value; }); })])
      .range([height, 0]);

  var z = d3.scaleCategory10();

  g.append("g")
      .attr("class", "axis axis--x")
      .attr("transform", "translate(0," + height + ")")
      .call(d3.axisBottom(x));

  var serie = g.selectAll(".serie")
      .data(series)
    .enter().append("g")
      .attr("class", "serie");

  serie.append("path")
      .attr("class", "line")
      .style("stroke", function(d) { return z(d[0].key); })
      .attr("d", d3.line()
          .x(function(d) { return x(d.date); })
          .y(function(d) { return y(d.value); }));

  var label = serie.selectAll(".label")
      .data(function(d) { return d; })
    .enter().append("g")
      .attr("class", "label")
      .attr("transform", function(d, i) { return "translate(" + x(d.date) + "," + y(d.value) + ")"; });

  label.append("text")
      .attr("dy", ".35em")
      .text(function(d) { return d.value; })
    .filter(function(d, i) { return i === data.length - 1; })
    .append("tspan")
      .attr("class", "label-key")
      .text(function(d) { return " " + d.key; });

  label.append("rect", "text")
      .datum(function() { return this.nextSibling.getBBox(); })
      .attr("x", function(d) { return d.x - labelPadding; })
      .attr("y", function(d) { return d.y - labelPadding; })
      .attr("width", function(d) { return d.width + 2 * labelPadding; })
      .attr("height", function(d) { return d.height + 2 * labelPadding; });
});

</script>

## thumbnail.png

      
    Raw
  

              thumbnail.png
	license: gpl-3.0
	redirect: https://observablehq.com/@d3/inline-labels
date	Apples	Bananas
2009	130	40
2010	137	58
2011	166	97
2012	154	117
2013	179	98
2014	187	120
2015	189	84
	<!DOCTYPE html>
	<meta charset="utf-8">
	<style>

	text {
	font: 10px sans-serif;
	}

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

	.line {
	fill: none;
	stroke-width: 1.5px;
	}

	.label {
	text-anchor: middle;
	}

	.label rect {
	fill: white;
	}

	.label-key {
	font-weight: bold;
	}

	</style>
	<svg width="960" height="500"></svg>
	<script src="//d3js.org/d3.v4.0.0-alpha.9.min.js"></script>
	<script>

	var parseTime = d3.timeParse("%Y");

	var svg = d3.select("svg");

	var margin = {top: 30, right: 50, bottom: 30, left: 30},
	width = +svg.attr("width") - margin.left - margin.right,
	height = +svg.attr("height") - margin.top - margin.bottom,
	labelPadding = 3;

	var g = svg.append("g")
	.attr("transform", "translate(" + margin.left + "," + margin.top + ")");

	d3.requestTsv("data.tsv", function(d) {
	d.date = parseTime(d.date);
	for (var k in d) if (k !== "date") d[k] = +d[k];
	return d;
	}, function(error, data) {
	if (error) throw error;

	var series = data.columns.slice(1).map(function(key) {
	return data.map(function(d) {
	return {
	key: key,
	date: d.date,
	value: d[key]
	};
	});
	});

	var x = d3.scaleTime()
	.domain([data[0].date, data[data.length - 1].date])
	.range([0, width]);

	var y = d3.scaleLinear()
	.domain([0, d3.max(series, function(s) { return d3.max(s, function(d) { return d.value; }); })])
	.range([height, 0]);

	var z = d3.scaleCategory10();

	g.append("g")
	.attr("class", "axis axis--x")
	.attr("transform", "translate(0," + height + ")")
	.call(d3.axisBottom(x));

	var serie = g.selectAll(".serie")
	.data(series)
	.enter().append("g")
	.attr("class", "serie");

	serie.append("path")
	.attr("class", "line")
	.style("stroke", function(d) { return z(d[0].key); })
	.attr("d", d3.line()
	.x(function(d) { return x(d.date); })
	.y(function(d) { return y(d.value); }));

	var label = serie.selectAll(".label")
	.data(function(d) { return d; })
	.enter().append("g")
	.attr("class", "label")
	.attr("transform", function(d, i) { return "translate(" + x(d.date) + "," + y(d.value) + ")"; });

	label.append("text")
	.attr("dy", ".35em")
	.text(function(d) { return d.value; })
	.filter(function(d, i) { return i === data.length - 1; })
	.append("tspan")
	.attr("class", "label-key")
	.text(function(d) { return " " + d.key; });

	label.append("rect", "text")
	.datum(function() { return this.nextSibling.getBBox(); })
	.attr("x", function(d) { return d.x - labelPadding; })
	.attr("y", function(d) { return d.y - labelPadding; })
	.attr("width", function(d) { return d.width + 2 * labelPadding; })
	.attr("height", function(d) { return d.height + 2 * labelPadding; });
	});

	</script>