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@dbuezas
Last active March 15, 2024 04:40
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Pie charts labels

This variation of a donut chart demonstrates how to add labels with lines. Clicking on the button changes the displayed data. Check Pie Chart with Labels and Missing Data to see how to handle transitions with missing/new data.

<!DOCTYPE html>
<meta charset="utf-8">
<style>
body {
font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
width: 960px;
height: 500px;
position: relative;
}
svg {
width: 100%;
height: 100%;
}
path.slice{
stroke-width:2px;
}
polyline{
opacity: .3;
stroke: black;
stroke-width: 2px;
fill: none;
}
</style>
<body>
<button class="randomize">randomize</button>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script>
var svg = d3.select("body")
.append("svg")
.append("g")
svg.append("g")
.attr("class", "slices");
svg.append("g")
.attr("class", "labels");
svg.append("g")
.attr("class", "lines");
var width = 960,
height = 450,
radius = Math.min(width, height) / 2;
var pie = d3.layout.pie()
.sort(null)
.value(function(d) {
return d.value;
});
var arc = d3.svg.arc()
.outerRadius(radius * 0.8)
.innerRadius(radius * 0.4);
var outerArc = d3.svg.arc()
.innerRadius(radius * 0.9)
.outerRadius(radius * 0.9);
svg.attr("transform", "translate(" + width / 2 + "," + height / 2 + ")");
var key = function(d){ return d.data.label; };
var color = d3.scale.ordinal()
.domain(["Lorem ipsum", "dolor sit", "amet", "consectetur", "adipisicing", "elit", "sed", "do", "eiusmod", "tempor", "incididunt"])
.range(["#98abc5", "#8a89a6", "#7b6888", "#6b486b", "#a05d56", "#d0743c", "#ff8c00"]);
function randomData (){
var labels = color.domain();
return labels.map(function(label){
return { label: label, value: Math.random() }
});
}
change(randomData());
d3.select(".randomize")
.on("click", function(){
change(randomData());
});
function change(data) {
/* ------- PIE SLICES -------*/
var slice = svg.select(".slices").selectAll("path.slice")
.data(pie(data), key);
slice.enter()
.insert("path")
.style("fill", function(d) { return color(d.data.label); })
.attr("class", "slice");
slice
.transition().duration(1000)
.attrTween("d", function(d) {
this._current = this._current || d;
var interpolate = d3.interpolate(this._current, d);
this._current = interpolate(0);
return function(t) {
return arc(interpolate(t));
};
})
slice.exit()
.remove();
/* ------- TEXT LABELS -------*/
var text = svg.select(".labels").selectAll("text")
.data(pie(data), key);
text.enter()
.append("text")
.attr("dy", ".35em")
.text(function(d) {
return d.data.label;
});
function midAngle(d){
return d.startAngle + (d.endAngle - d.startAngle)/2;
}
text.transition().duration(1000)
.attrTween("transform", function(d) {
this._current = this._current || d;
var interpolate = d3.interpolate(this._current, d);
this._current = interpolate(0);
return function(t) {
var d2 = interpolate(t);
var pos = outerArc.centroid(d2);
pos[0] = radius * (midAngle(d2) < Math.PI ? 1 : -1);
return "translate("+ pos +")";
};
})
.styleTween("text-anchor", function(d){
this._current = this._current || d;
var interpolate = d3.interpolate(this._current, d);
this._current = interpolate(0);
return function(t) {
var d2 = interpolate(t);
return midAngle(d2) < Math.PI ? "start":"end";
};
});
text.exit()
.remove();
/* ------- SLICE TO TEXT POLYLINES -------*/
var polyline = svg.select(".lines").selectAll("polyline")
.data(pie(data), key);
polyline.enter()
.append("polyline");
polyline.transition().duration(1000)
.attrTween("points", function(d){
this._current = this._current || d;
var interpolate = d3.interpolate(this._current, d);
this._current = interpolate(0);
return function(t) {
var d2 = interpolate(t);
var pos = outerArc.centroid(d2);
pos[0] = radius * 0.95 * (midAngle(d2) < Math.PI ? 1 : -1);
return [arc.centroid(d2), outerArc.centroid(d2), pos];
};
});
polyline.exit()
.remove();
};
</script>
</body>
@dbuezas
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dbuezas commented Mar 24, 2023

Oh, I see, a client project. Well happy to hear it helped somebody :)

@JosephStarobinets
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Hi @dbuezas,

Thank you very much for the code.

I made some small changes to make this code work in version 7:

var pie = d3.pie() //deleted layout.
var arc = d3.arc() //svg.
var outerArc = d3.arc() //.svg
var color = d3.scaleOrdinal()//.scale.ordinal()

Everything works fine except for one thing: when I first open the page (and the 'change' function is called for the first time), the graph doesn't display, and all the text collapses to the center. Do you have any thoughts on why this might be happening?
image

@dbuezas
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dbuezas commented Oct 26, 2023

It looks like the arc radius starts as zero. I suggest you make your changes one by one and find which one is problematic

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