simple-venn
v0.2.3
Published
Small package to create two-ring, area-proportional Venn diagrams.
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matthewbryancurtisReadme
simple-venn
simple-venn is a tiny JavaScript library for area-proportional, two-ringed Venn diagrams. A lot of the math in this library is pulled from benfred's Venn.js library - a great library for Venn diagrams with 3+ sets, but overkill for what I needed.
simple-venn was created with the end goal of giving developers access to the underlying dimensions of the Venn diagram. In the /examples directory, you'll see that simple-venn can be used with canvas or regular divs. I personally made it to be used with regl. It should give you all the math to position the sets as you see fit.
However I wanted simple-venn to be...simple. So it has some built-in drawing functionality using canvas. This way it's super easy to get drawing Venn diagrams:
<!DOCTYPE html>
<html>
<head>
<title>SimpleVenn</title>
</head>
<body></body>
<script src="simple-venn.dist.js"></script>
<script>
var aSet = 120000;
var bSet = 120000;
var uSet = 60000;
var scale = 0.5;
// Appends canvas element to body and draws Venn
new SimpleVenn(aSet, bSet, uSet, scale).draw();
</script>
</html>API
Constructor
new SimpleVenn(aSetCount, bSetCount, uSetCount, scale)| parameter | type | details | | --- | --- | --- | | aSetCount | Number | Value for set A | | bSetCount | Number | Value for set B | | uSetCount | Number | Value for set intersection | | scale (optional) | Number | Set area is determined by count and scaled up or down by this scale factor (default: 1) |
Each parameter can be accessed and updated directly from the returned SimpleVenn object.
let venn = new SimpleVenn(4, 4, 2);
console.log(venn.scale); // 1
venn.scale = 2;
console.log(venn.scale); // 2Computed Properties
Besides the four initial properties, all other properties are computed when accessed.
| property | description | | --- | --- | | aSetArea | The area of set A | | bSetArea | The area of set B | | uSetArea | The area of set intersection | | aSetRadius | The radius of set A | | bSetRadius | The radius of set B | | aSetDiameter | The diameter of set A | | bSetDiameter | The diameter of set B | | setDistance | The approximate distance between the center of set A and the center of set B so the overlap area is proportional to the overlap value | | aSetIntersectDist | The distance from the center of set A to the point of intersection between the two sets | | bSetIntersectDist | The distance from the center of set B to the point of intersection between the two sets |
Methods
SimpleVenn.draw(selector, options);While this library is more about the math of Venn diagrams (so you can do what you want with the results), this is a method that will just draw it for you.
| parameter | type | details | | --- | --- | --- | | selector (optional) | String | Selector for the element the Venn diagram will be appended to or the canvas object the diagram will be drawn on | | options (optional) | Object | An object specifying styles for the Venn diagram |
If a selector is not provided, simple-venn will append a canvas element to the body of the document, sized to the full viewport size. If the selected element is a canvas element, simple-venn will draw the diagram on the canvas element. Otherwise simple-venn will append a canvas element to the selected element that is the full size of the element. Under the hood, simple-venn uses querySelectorAll and will try to draw to all matches.
The options object will look for these properties:
| property | Type | description | | --- | --- | --- | | aSetColor (optional) | String | The color of set A (default: '#00F') | | bSetColor (optional) | String | The color of set B (default: '#0F0') | | opacity (optional) | Number | The opacity of each set (default: 0.5) |
Recommended use:
<div id="venn" style="width: 500px; height: 500px;"></div>
<script>
const venn = new SimpleVenn(60000, 60000, 30000);
venn.draw('#venn');
</script>Contributing
Please do! As long as you're cool about it (no jerks). Feel free to file an issue for bugs and feature requests. Before working on a PR, it might be good to check if it's needed in the library. It could certainly use some math review, optimizations, and testing.
License
MIT