venn.js
A javascript library for laying out area proportional venn and euler diagrams.
Details of how this library works can be found on the blog
post
I wrote about this. A follow up post discusses testing strategy and
algorithmic improvements.
Installing
If you use NPM, npm install venn.js
. Otherwise, download the latest release.
Usage
This library depends on d3.js to display the venn
diagrams.
Simple layout
To lay out a simple diagram, just define the sets and their sizes along with the sizes
of all the set intersections.
The VennDiagram object will calculate a layout that is proportional to the
input sizes, and display it in the appropriate selection when called:
var sets = [ {sets: ['A'], size: 12},
{sets: ['B'], size: 12},
{sets: ['A','B'], size: 2}];
var chart = venn.VennDiagram()
d3.select("#venn").datum(sets).call(chart);
View this example
Changing the Style
The style of the Venn Diagram can be customized by using D3 after the diagram
has been drawn. For instance to draw a Venn Diagram with white text and a darker fill:
var chart = venn.VennDiagram()
d3.select("#inverted").datum(sets).call(chart)
d3.selectAll("#inverted .venn-circle path")
.style("fill-opacity", .8);
d3.selectAll("#inverted text").style("fill", "white");
View this example, along with other possible styles
Dynamic layout
To have a layout that reacts to a change in input, all that you need to do is
update the dataset and call the chart again:
var chart = venn.VennDiagram()
d3.select("#venn").datum(getSetIntersections()).call(chart);
d3.selectAll("input").on("change", function() {
d3.select("#venn").datum(getSetIntersections()).call(chart);
});
View this example
Making the diagram interactive
Making the diagram interactive is basically the same idea as changing the style: just add event listeners to the elements in the venn diagram. To change the text size and circle colours on mouseover:
d3.selectAll("#rings .venn-circle")
.on("mouseover", function(d, i) {
var node = d3.select(this).transition();
node.select("path").style("fill-opacity", .2);
node.select("text").style("font-weight", "100")
.style("font-size", "36px");
})
.on("mouseout", function(d, i) {
var node = d3.select(this).transition();
node.select("path").style("fill-opacity", 0);
node.select("text").style("font-weight", "100")
.style("font-size", "24px");
});
View this example
Adding tooltips
Another common case is adding a tooltip when hovering over the elements in the diagram. The only
tricky thing here is maintaining the correct Z-order so that the smallest intersection areas
are on top, while still making the area that is being hovered over appear on top of the others:
var div = d3.select("#venn")
div.datum(sets).call(venn.VennDiagram());
var tooltip = d3.select("body").append("div")
.attr("class", "venntooltip");
div.selectAll("g")
.on("mouseover", function(d, i) {
venn.sortAreas(div, d);
tooltip.transition().duration(400).style("opacity", .9);
tooltip.text(d.size + " users");
var selection = d3.select(this).transition("tooltip").duration(400);
selection.select("path")
.style("stroke-width", 3)
.style("fill-opacity", d.sets.length == 1 ? .4 : .1)
.style("stroke-opacity", 1);
})
.on("mousemove", function() {
tooltip.style("left", (d3.event.pageX) + "px")
.style("top", (d3.event.pageY - 28) + "px");
})
.on("mouseout", function(d, i) {
tooltip.transition().duration(400).style("opacity", 0);
var selection = d3.select(this).transition("tooltip").duration(400);
selection.select("path")
.style("stroke-width", 0)
.style("fill-opacity", d.sets.length == 1 ? .25 : .0)
.style("stroke-opacity", 0);
});
View this example
Released under the MIT License.