Skip to content

Instantly share code, notes, and snippets.

@nbremer
Last active Jun 12, 2016
Embed
What would you like to do?
Stretched Chord - Step 3 - How to make the two sections symmetrical
height: 670
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8"/>
<title>Stretched Chord to show Flows</title>
<!-- D3.js -->
<script src="http://d3js.org/d3.v3.js"></script>
<!-- jQuery -->
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<!-- Open Sans & CSS -->
<link href='http://fonts.googleapis.com/css?family=Open+Sans:700,400,300' rel='stylesheet' type='text/css'>
<style>
body {
font-family: 'Open Sans', sans-serif;
font-size: 12px;
font-weight: 400;
color: #525252;
text-align: center;
}
line {
stroke: #000;
stroke-width: 1.px;
}
text {
font-size: 8px;
}
.titles{
font-size: 10px;
}
path.chord {
fill-opacity: .80;
}
</style>
</head>
<body>
<div id="chart"></div>
<script src="script.js"></script>
</body>
</html>
////////////////////////////////////////////////////////////
//////////////////////// Set-up ////////////////////////////
////////////////////////////////////////////////////////////
var screenWidth = $(window).width();
var margin = {left: 50, top: 10, right: 50, bottom: 10},
width = Math.min(screenWidth, 800) - margin.left - margin.right,
height = Math.min(screenWidth, 800)*5/6 - margin.top - margin.bottom;
var svg = d3.select("#chart").append("svg")
.attr("width", (width + margin.left + margin.right))
.attr("height", (height + margin.top + margin.bottom));
var wrapper = svg.append("g").attr("class", "chordWrapper")
.attr("transform", "translate(" + (width / 2 + margin.left) + "," + (height / 2 + margin.top) + ")");;
var outerRadius = Math.min(width, height) / 2 - 100,
innerRadius = outerRadius * 0.95,
opacityDefault = 0.7; //default opacity of chords
////////////////////////////////////////////////////////////
////////////////////////// Data ////////////////////////////
////////////////////////////////////////////////////////////
var Names = ["X","Y","Z","Dummy","C","B","A","Dummy"];
var respondents = 95, //Total number of respondents (i.e. the number that makes up the group)
emptyPerc = 0.4, //What % of the circle should become empty in comparison to the visible arcs
emptyStroke = Math.round(respondents*emptyPerc); //How many "units" would define this empty percentage
var matrix = [
[0,0,0,0,10,5,15,0], //X
[0,0,0,0,5,15,20,0], //Y
[0,0,0,0,15,5,5,0], //Z
[0,0,0,0,0,0,0,emptyStroke], //Dummy stroke
[10,5,15,0,0,0,0,0], //C
[5,15,5,0,0,0,0,0], //B
[15,20,5,0,0,0,0,0], //A
[0,0,0,emptyStroke,0,0,0,0] //Dummy stroke
];
//Calculate how far the Chord Diagram needs to be rotated clockwise
//to make the dummy invisible chord center vertically
var offset = Math.PI * (emptyStroke/(respondents + emptyStroke)) / 2;
var chord = d3.layout.chord()
.padding(.02)
.sortSubgroups(d3.descending) //sort the chords inside an arc from high to low
.sortChords(d3.descending) //which chord should be shown on top when chords cross. Now the biggest chord is at the bottom
.matrix(matrix);
var arc = d3.svg.arc()
.innerRadius(innerRadius)
.outerRadius(outerRadius)
.startAngle(startAngle) //startAngle and endAngle now include the offset in degrees
.endAngle(endAngle);
var path = d3.svg.chord()
.radius(innerRadius)
.startAngle(startAngle)
.endAngle(endAngle);
var fill = d3.scale.ordinal()
.domain(d3.range(Names.length))
.range(["#C4C4C4","#C4C4C4","#C4C4C4","#E0E0E0","#EDC951","#CC333F","#00A0B0","#E0E0E0"]);
////////////////////////////////////////////////////////////
//////////////////// Draw outer Arcs ///////////////////////
////////////////////////////////////////////////////////////
var g = wrapper.selectAll("g.group")
.data(chord.groups)
.enter().append("g")
.attr("class", "group");;
g.append("path")
.style("stroke", function(d) { return fill(d.index); })
.style("fill", function(d) { return fill(d.index); })
.attr("d", arc);
////////////////////////////////////////////////////////////
////////////////////// Append Names ////////////////////////
////////////////////////////////////////////////////////////
//The text needs to be rotated with the offset in the clockwise direction
g.append("text")
.each(function(d) { d.angle = ((d.startAngle + d.endAngle) / 2) + offset;}) //Slightly altered function to define the angle
.attr("dy", ".35em")
.attr("class", "titles")
.attr("text-anchor", function(d) { return d.angle > Math.PI ? "end" : null; })
.attr("transform", function(d,i) {
var c = arc.centroid(d);
return "rotate(" + (d.angle * 180 / Math.PI - 90) + ")"
+ "translate(" + (innerRadius + 55) + ")"
+ (d.angle > Math.PI ? "rotate(180)" : "")
})
.text(function(d,i) { return Names[i]; });
////////////////////////////////////////////////////////////
//////////////////// Draw inner chords /////////////////////
////////////////////////////////////////////////////////////
var chords = wrapper.selectAll("path.chord")
.data(chord.chords)
.enter().append("path")
.attr("class", "chord")
.style("stroke", "none")
.style("fill", function(d,i) { return fill(d.target.index); })
.style("opacity", opacityDefault)
.attr("d", path);
////////////////////////////////////////////////////////////
///////////////////////// Tooltip //////////////////////////
////////////////////////////////////////////////////////////
//Arcs
g.append("title")
.text(function(d, i) {return Math.round(d.value) + " people in " + Names[i];});
//Chords
chords.append("title")
.text(function(d) {
return [Math.round(d.source.value), " people from ", Names[d.target.index], " to ", Names[d.source.index]].join("");
});
////////////////////////////////////////////////////////////
////////////////// Extra Functions /////////////////////////
////////////////////////////////////////////////////////////
//Include the offset in de start and end angle to rotate the Chord diagram clockwise
function startAngle(d) { return d.startAngle + offset; }
function endAngle(d) { return d.endAngle + offset; }
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment