Skip to content

Instantly share code, notes, and snippets.

@micahstubbs
Last active July 17, 2020 04:59
Show Gist options
  • Star 0 You must be signed in to star a gist
  • Fork 0 You must be signed in to fork a gist
  • Save micahstubbs/ad5ac2813a8edb04ab87e7e033515cb9 to your computer and use it in GitHub Desktop.
Save micahstubbs/ad5ac2813a8edb04ab87e7e033515cb9 to your computer and use it in GitHub Desktop.
fisheye magnifier with fixed focus
border: none
height: 660
license: CC0-1.0

This time with a fixed, hard-coded focus

a further iteration on the block Fisheye Magnifying Glass from @micahstubbs


an iteration on @fernoftheandes's bl.ock Encircling D3's Fisheye Distortion that uses ES2015 syntax


Original README.md

Except for the code segments that render the magnifying glass (as circle or path), this is essentially a copy of Mike Bostock's Fisheye Distortion example.

The motivation for this was largely aesthetical but also a bit functional. When using the Fisheye as an aid to viewing large datasets, I often find myself experimenting with the degree and radius of the distortion. In such cases, I find it helpful to see the exact reach of the distortion and then decide the best configuration for a particular dataset.

;(function() {
d3.fisheye = {
scale: function(scaleType) {
return d3_fisheye_scale(scaleType(), 3, 0)
},
circular: function() {
var radius = 200,
distortion = 2,
k0,
k1,
focus = [0, 0]
function fisheye(d) {
var dx = d.x - focus[0],
dy = d.y - focus[1],
dd = Math.sqrt(dx * dx + dy * dy)
if (!dd || dd >= radius) return { x: d.x, y: d.y, z: 1 }
var k = ((k0 * (1 - Math.exp(-dd * k1))) / dd) * 0.75 + 0.25
return {
x: focus[0] + dx * k,
y: focus[1] + dy * k,
z: Math.min(k, 10),
}
}
function rescale() {
k0 = Math.exp(distortion)
k0 = (k0 / (k0 - 1)) * radius
k1 = distortion / radius
return fisheye
}
fisheye.radius = function(_) {
if (!arguments.length) return radius
radius = +_
return rescale()
}
fisheye.distortion = function(_) {
if (!arguments.length) return distortion
distortion = +_
return rescale()
}
fisheye.focus = function(_) {
if (!arguments.length) return focus
focus = _
return fisheye
}
return rescale()
},
}
function d3_fisheye_scale(scale, d, a) {
function fisheye(_) {
var x = scale(_),
left = x < a,
range = d3.extent(scale.range()),
min = range[0],
max = range[1],
m = left ? a - min : max - a
if (m == 0) m = max - min
return ((left ? -1 : 1) * m * (d + 1)) / (d + m / Math.abs(x - a)) + a
}
fisheye.distortion = function(_) {
if (!arguments.length) return d
d = +_
return fisheye
}
fisheye.focus = function(_) {
if (!arguments.length) return a
a = +_
return fisheye
}
fisheye.copy = function() {
return d3_fisheye_scale(scale.copy(), d, a)
}
fisheye.nice = scale.nice
fisheye.ticks = scale.ticks
fisheye.tickFormat = scale.tickFormat
return d3.rebind(fisheye, scale, 'domain', 'range')
}
})()
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title>Encircling D3 Fisheye Distortion</title>
<script type="text/javascript" src="https://d3js.org/d3.v3.min.js"></script>
<script src="https://npmcdn.com/babel-core@5.8.34/browser.min.js"></script>
<script type="text/javascript" src="fisheye.js"></script>
<style>
.background {
fill: none;
pointer-events: all;
}
/*
#chart1 {
width: 960px;
height: 600px;
border: solid 1px #ccc;
}
*/
#chart1 .circle {
stroke: #fff;
stroke-width: 1.5px;
}
#chart1 .link {
stroke: #999;
stroke-opacity: 0.6;
stroke-width: 1.5px;
}
text {
font: 12px sans-serif;
pointer-events: none;
text-anchor: start;
}
/* magnifier glass as circle */
.lens {
stroke: gray;
stroke-width: 2px;
stroke-opacity: 0;
fill: none;
}
/* magnifier glass as path */
.mag {
stroke: gray;
stroke-width: 2px;
stroke-opacity: 0;
fill: none;
}
/* magnifier handle as path */
.mag2 {
stroke: black;
stroke-width: 6px;
stroke-linecap: round;
fill: none;
}
</style>
</head>
<body bgcolor="white">
<form style="margin-left: 20px;">
<input type="radio" name="wot" id="circle" value="one" />&nbsp;as
circle<br />
<input type="radio" name="wot" id="path" value="two" checked />&nbsp;as
path
</form>
<div id="chart1"></div>
<script src="./index.js"></script>
</body>
</html>
const width = 960
const height = 600
const color = d3.scale.category20()
const fisheye = d3.fisheye.circular().radius(100).distortion(5)
const force = d3.layout
.force()
.charge(-440)
.linkDistance(60)
.size([width, height])
const svg = d3.select('#chart1').append('svg').attr({
width,
height,
})
// magnifier as circle
const lens = svg
.append('circle')
.attr('class', 'lens')
.attr('r', fisheye.radius())
// magnifier as path
const mag = svg.append('path').attr('class', 'mag')
// magnifier handle as path
const mag2 = svg.append('path').attr('class', 'mag2')
// magnifier handle as path
const mag3 = svg.append('path').attr('class', 'mag2')
/*
svg.append('rect')
.attr('class', 'background')
.attr('width', width)
.attr('height', height);
*/
d3.json('miserables.json', (data) => {
const n = data.nodes.length
force.nodes(data.nodes).links(data.links)
// Initialize the positions deterministically, for better results.
data.nodes.forEach((d, i) => {
d.x = d.y = (width / n) * i
})
// Run the layout a fixed number of times.
// The ideal number of times scales with graph complexity.
// Of course, don't run too long—you'll hang the page!
force.start()
for (let i = n; i > 0; --i) force.tick()
force.stop()
// Center the nodes in the middle.
let ox = 0
let oy = 0
data.nodes.forEach((d) => {
ox += d.x
oy += d.y
})
ox = ox / n - width / 2
oy = oy / n - height / 2
data.nodes.forEach((d) => {
d.x -= ox
d.y -= oy
})
const link = svg
.selectAll('.link')
.data(data.links)
.enter()
.append('line')
.attr('class', 'link')
.attr('x1', (d) => d.source.x)
.attr('y1', (d) => d.source.y)
.attr('x2', (d) => d.target.x)
.attr('y2', (d) => d.target.y)
.style('stroke-width', (d) => Math.sqrt(d.value))
const node = svg
.selectAll('.node')
.data(data.nodes)
.enter()
.append('g')
.attr('class', 'node')
render('path')
function render(shape) {
node.selectAll('.link').remove()
node.selectAll('.circle').remove()
node.selectAll('.text').remove()
lens.style('stroke-opacity', shape === 'circle' ? 1 : 0)
mag.style('stroke-opacity', shape === 'path' ? 1 : 0)
mag2.style('stroke-opacity', shape === 'path' ? 1 : 0)
mag3.style('stroke-opacity', shape === 'path' ? 1 : 0)
const nodeEnter = node
.append('circle')
.attr('class', 'circle')
.attr('cx', (d) => d.x)
.attr('cy', (d) => d.y)
.attr('r', 6)
.style('fill', (d) => color(d.group))
.call(force.drag)
const text = node
.append('text')
.attr('class', 'text')
.attr('dy', (d) => d.y)
.attr('dx', (d) => d.x)
.text((d) => d.name)
node.append('title').text((d) => d.name)
// svg.on('mousemove', function () {
//
// here is where we add the fixed focus
//
const focus = { x: 380, y: 100 }
fisheye.focus([focus.x, focus.y])
// fisheye.focus(d3.mouse(this))
const mouseX = focus.x // d3.mouse(this)[0]
const mouseY = focus.y // d3.mouse(this)[1]
const r = fisheye.radius()
if (shape === 'circle') {
// display magnifier as circle
lens.attr('cx', mouseX).attr('cy', mouseY)
} else {
// path for magnifier
const magPath = `M ${mouseX},${mouseY} m -${r}, 0 a ${r},${r} 0 1,0 ${
r * 2
},0 a ${r},${r} 0 1,0 -${r * 2},0`
//
// path for magnifier's handle
//
// specify angle where magnifier handle should 'attach' to body
const omegaTop = 1.15 * Math.PI
// point in circumference to attach top magnifier handle
const xt1 = mouseX + r * Math.sin(omegaTop)
const yt1 = mouseY + r * Math.cos(omegaTop)
const magHandleTop = `M${xt1 - 10},${yt1 + 2} L60,${mouseY} + r}`
// specify angle where magnifier handle should 'attach' to body
const omegaBottom = 1.85 * Math.PI
// point in circumference to attach bottom magnifier handle
const xb1 = mouseX + r * Math.sin(omegaBottom)
const yb1 = mouseY + r * Math.cos(omegaBottom)
const magHandleBottom = `M${xb1 - 10},${yb1 + 2} L60,${+r}`
// display magnifier as path
mag.attr('d', magPath)
// display magnifier handle as path
mag2.attr('d', magHandleTop)
// display magnifier handle as path
mag3.attr('d', magHandleBottom)
}
nodeEnter
.each((d) => {
d.fisheye = fisheye(d)
})
.attr('cx', (d) => d.fisheye.x)
.attr('cy', (d) => d.fisheye.y)
.attr('r', (d) => d.fisheye.z * 4.5)
text.attr('dx', (d) => d.fisheye.x).attr('dy', (d) => d.fisheye.y)
link
.attr('x1', (d) => d.source.fisheye.x)
.attr('y1', (d) => d.source.fisheye.y)
.attr('x2', (d) => d.target.fisheye.x)
.attr('y2', (d) => d.target.fisheye.y)
// }) // end svg.on('mousemove')
}
d3.select('#circle').on('click', () => {
render('circle')
})
d3.select('#path').on('click', () => {
render('path')
})
})
{
"nodes":[
{"name":"Myriel","group":1},
{"name":"Napoleon","group":1},
{"name":"Mlle.Baptistine","group":1},
{"name":"Mme.Magloire","group":1},
{"name":"CountessdeLo","group":1},
{"name":"Geborand","group":1},
{"name":"Champtercier","group":1},
{"name":"Cravatte","group":1},
{"name":"Count","group":1},
{"name":"OldMan","group":1},
{"name":"Labarre","group":2},
{"name":"Valjean","group":2},
{"name":"Marguerite","group":3},
{"name":"Mme.deR","group":2},
{"name":"Isabeau","group":2},
{"name":"Gervais","group":2},
{"name":"Tholomyes","group":3},
{"name":"Listolier","group":3},
{"name":"Fameuil","group":3},
{"name":"Blacheville","group":3},
{"name":"Favourite","group":3},
{"name":"Dahlia","group":3},
{"name":"Zephine","group":3},
{"name":"Fantine","group":3},
{"name":"Mme.Thenardier","group":4},
{"name":"Thenardier","group":4},
{"name":"Cosette","group":5},
{"name":"Javert","group":4},
{"name":"Fauchelevent","group":0},
{"name":"Bamatabois","group":2},
{"name":"Perpetue","group":3},
{"name":"Simplice","group":2},
{"name":"Scaufflaire","group":2},
{"name":"Woman1","group":2},
{"name":"Judge","group":2},
{"name":"Champmathieu","group":2},
{"name":"Brevet","group":2},
{"name":"Chenildieu","group":2},
{"name":"Cochepaille","group":2},
{"name":"Pontmercy","group":4},
{"name":"Boulatruelle","group":6},
{"name":"Eponine","group":4},
{"name":"Anzelma","group":4},
{"name":"Woman2","group":5},
{"name":"MotherInnocent","group":0},
{"name":"Gribier","group":0},
{"name":"Jondrette","group":7},
{"name":"Mme.Burgon","group":7},
{"name":"Gavroche","group":8},
{"name":"Gillenormand","group":5},
{"name":"Magnon","group":5},
{"name":"Mlle.Gillenormand","group":5},
{"name":"Mme.Pontmercy","group":5},
{"name":"Mlle.Vaubois","group":5},
{"name":"Lt.Gillenormand","group":5},
{"name":"Marius","group":8},
{"name":"BaronessT","group":5},
{"name":"Mabeuf","group":8},
{"name":"Enjolras","group":8},
{"name":"Combeferre","group":8},
{"name":"Prouvaire","group":8},
{"name":"Feuilly","group":8},
{"name":"Courfeyrac","group":8},
{"name":"Bahorel","group":8},
{"name":"Bossuet","group":8},
{"name":"Joly","group":8},
{"name":"Grantaire","group":8},
{"name":"MotherPlutarch","group":9},
{"name":"Gueulemer","group":4},
{"name":"Babet","group":4},
{"name":"Claquesous","group":4},
{"name":"Montparnasse","group":4},
{"name":"Toussaint","group":5},
{"name":"Child1","group":10},
{"name":"Child2","group":10},
{"name":"Brujon","group":4},
{"name":"Mme.Hucheloup","group":8}
],
"links":[
{"source":1,"target":0,"value":1},
{"source":2,"target":0,"value":8},
{"source":3,"target":0,"value":10},
{"source":3,"target":2,"value":6},
{"source":4,"target":0,"value":1},
{"source":5,"target":0,"value":1},
{"source":6,"target":0,"value":1},
{"source":7,"target":0,"value":1},
{"source":8,"target":0,"value":2},
{"source":9,"target":0,"value":1},
{"source":11,"target":10,"value":1},
{"source":11,"target":3,"value":3},
{"source":11,"target":2,"value":3},
{"source":11,"target":0,"value":5},
{"source":12,"target":11,"value":1},
{"source":13,"target":11,"value":1},
{"source":14,"target":11,"value":1},
{"source":15,"target":11,"value":1},
{"source":17,"target":16,"value":4},
{"source":18,"target":16,"value":4},
{"source":18,"target":17,"value":4},
{"source":19,"target":16,"value":4},
{"source":19,"target":17,"value":4},
{"source":19,"target":18,"value":4},
{"source":20,"target":16,"value":3},
{"source":20,"target":17,"value":3},
{"source":20,"target":18,"value":3},
{"source":20,"target":19,"value":4},
{"source":21,"target":16,"value":3},
{"source":21,"target":17,"value":3},
{"source":21,"target":18,"value":3},
{"source":21,"target":19,"value":3},
{"source":21,"target":20,"value":5},
{"source":22,"target":16,"value":3},
{"source":22,"target":17,"value":3},
{"source":22,"target":18,"value":3},
{"source":22,"target":19,"value":3},
{"source":22,"target":20,"value":4},
{"source":22,"target":21,"value":4},
{"source":23,"target":16,"value":3},
{"source":23,"target":17,"value":3},
{"source":23,"target":18,"value":3},
{"source":23,"target":19,"value":3},
{"source":23,"target":20,"value":4},
{"source":23,"target":21,"value":4},
{"source":23,"target":22,"value":4},
{"source":23,"target":12,"value":2},
{"source":23,"target":11,"value":9},
{"source":24,"target":23,"value":2},
{"source":24,"target":11,"value":7},
{"source":25,"target":24,"value":13},
{"source":25,"target":23,"value":1},
{"source":25,"target":11,"value":12},
{"source":26,"target":24,"value":4},
{"source":26,"target":11,"value":31},
{"source":26,"target":16,"value":1},
{"source":26,"target":25,"value":1},
{"source":27,"target":11,"value":17},
{"source":27,"target":23,"value":5},
{"source":27,"target":25,"value":5},
{"source":27,"target":24,"value":1},
{"source":27,"target":26,"value":1},
{"source":28,"target":11,"value":8},
{"source":28,"target":27,"value":1},
{"source":29,"target":23,"value":1},
{"source":29,"target":27,"value":1},
{"source":29,"target":11,"value":2},
{"source":30,"target":23,"value":1},
{"source":31,"target":30,"value":2},
{"source":31,"target":11,"value":3},
{"source":31,"target":23,"value":2},
{"source":31,"target":27,"value":1},
{"source":32,"target":11,"value":1},
{"source":33,"target":11,"value":2},
{"source":33,"target":27,"value":1},
{"source":34,"target":11,"value":3},
{"source":34,"target":29,"value":2},
{"source":35,"target":11,"value":3},
{"source":35,"target":34,"value":3},
{"source":35,"target":29,"value":2},
{"source":36,"target":34,"value":2},
{"source":36,"target":35,"value":2},
{"source":36,"target":11,"value":2},
{"source":36,"target":29,"value":1},
{"source":37,"target":34,"value":2},
{"source":37,"target":35,"value":2},
{"source":37,"target":36,"value":2},
{"source":37,"target":11,"value":2},
{"source":37,"target":29,"value":1},
{"source":38,"target":34,"value":2},
{"source":38,"target":35,"value":2},
{"source":38,"target":36,"value":2},
{"source":38,"target":37,"value":2},
{"source":38,"target":11,"value":2},
{"source":38,"target":29,"value":1},
{"source":39,"target":25,"value":1},
{"source":40,"target":25,"value":1},
{"source":41,"target":24,"value":2},
{"source":41,"target":25,"value":3},
{"source":42,"target":41,"value":2},
{"source":42,"target":25,"value":2},
{"source":42,"target":24,"value":1},
{"source":43,"target":11,"value":3},
{"source":43,"target":26,"value":1},
{"source":43,"target":27,"value":1},
{"source":44,"target":28,"value":3},
{"source":44,"target":11,"value":1},
{"source":45,"target":28,"value":2},
{"source":47,"target":46,"value":1},
{"source":48,"target":47,"value":2},
{"source":48,"target":25,"value":1},
{"source":48,"target":27,"value":1},
{"source":48,"target":11,"value":1},
{"source":49,"target":26,"value":3},
{"source":49,"target":11,"value":2},
{"source":50,"target":49,"value":1},
{"source":50,"target":24,"value":1},
{"source":51,"target":49,"value":9},
{"source":51,"target":26,"value":2},
{"source":51,"target":11,"value":2},
{"source":52,"target":51,"value":1},
{"source":52,"target":39,"value":1},
{"source":53,"target":51,"value":1},
{"source":54,"target":51,"value":2},
{"source":54,"target":49,"value":1},
{"source":54,"target":26,"value":1},
{"source":55,"target":51,"value":6},
{"source":55,"target":49,"value":12},
{"source":55,"target":39,"value":1},
{"source":55,"target":54,"value":1},
{"source":55,"target":26,"value":21},
{"source":55,"target":11,"value":19},
{"source":55,"target":16,"value":1},
{"source":55,"target":25,"value":2},
{"source":55,"target":41,"value":5},
{"source":55,"target":48,"value":4},
{"source":56,"target":49,"value":1},
{"source":56,"target":55,"value":1},
{"source":57,"target":55,"value":1},
{"source":57,"target":41,"value":1},
{"source":57,"target":48,"value":1},
{"source":58,"target":55,"value":7},
{"source":58,"target":48,"value":7},
{"source":58,"target":27,"value":6},
{"source":58,"target":57,"value":1},
{"source":58,"target":11,"value":4},
{"source":59,"target":58,"value":15},
{"source":59,"target":55,"value":5},
{"source":59,"target":48,"value":6},
{"source":59,"target":57,"value":2},
{"source":60,"target":48,"value":1},
{"source":60,"target":58,"value":4},
{"source":60,"target":59,"value":2},
{"source":61,"target":48,"value":2},
{"source":61,"target":58,"value":6},
{"source":61,"target":60,"value":2},
{"source":61,"target":59,"value":5},
{"source":61,"target":57,"value":1},
{"source":61,"target":55,"value":1},
{"source":62,"target":55,"value":9},
{"source":62,"target":58,"value":17},
{"source":62,"target":59,"value":13},
{"source":62,"target":48,"value":7},
{"source":62,"target":57,"value":2},
{"source":62,"target":41,"value":1},
{"source":62,"target":61,"value":6},
{"source":62,"target":60,"value":3},
{"source":63,"target":59,"value":5},
{"source":63,"target":48,"value":5},
{"source":63,"target":62,"value":6},
{"source":63,"target":57,"value":2},
{"source":63,"target":58,"value":4},
{"source":63,"target":61,"value":3},
{"source":63,"target":60,"value":2},
{"source":63,"target":55,"value":1},
{"source":64,"target":55,"value":5},
{"source":64,"target":62,"value":12},
{"source":64,"target":48,"value":5},
{"source":64,"target":63,"value":4},
{"source":64,"target":58,"value":10},
{"source":64,"target":61,"value":6},
{"source":64,"target":60,"value":2},
{"source":64,"target":59,"value":9},
{"source":64,"target":57,"value":1},
{"source":64,"target":11,"value":1},
{"source":65,"target":63,"value":5},
{"source":65,"target":64,"value":7},
{"source":65,"target":48,"value":3},
{"source":65,"target":62,"value":5},
{"source":65,"target":58,"value":5},
{"source":65,"target":61,"value":5},
{"source":65,"target":60,"value":2},
{"source":65,"target":59,"value":5},
{"source":65,"target":57,"value":1},
{"source":65,"target":55,"value":2},
{"source":66,"target":64,"value":3},
{"source":66,"target":58,"value":3},
{"source":66,"target":59,"value":1},
{"source":66,"target":62,"value":2},
{"source":66,"target":65,"value":2},
{"source":66,"target":48,"value":1},
{"source":66,"target":63,"value":1},
{"source":66,"target":61,"value":1},
{"source":66,"target":60,"value":1},
{"source":67,"target":57,"value":3},
{"source":68,"target":25,"value":5},
{"source":68,"target":11,"value":1},
{"source":68,"target":24,"value":1},
{"source":68,"target":27,"value":1},
{"source":68,"target":48,"value":1},
{"source":68,"target":41,"value":1},
{"source":69,"target":25,"value":6},
{"source":69,"target":68,"value":6},
{"source":69,"target":11,"value":1},
{"source":69,"target":24,"value":1},
{"source":69,"target":27,"value":2},
{"source":69,"target":48,"value":1},
{"source":69,"target":41,"value":1},
{"source":70,"target":25,"value":4},
{"source":70,"target":69,"value":4},
{"source":70,"target":68,"value":4},
{"source":70,"target":11,"value":1},
{"source":70,"target":24,"value":1},
{"source":70,"target":27,"value":1},
{"source":70,"target":41,"value":1},
{"source":70,"target":58,"value":1},
{"source":71,"target":27,"value":1},
{"source":71,"target":69,"value":2},
{"source":71,"target":68,"value":2},
{"source":71,"target":70,"value":2},
{"source":71,"target":11,"value":1},
{"source":71,"target":48,"value":1},
{"source":71,"target":41,"value":1},
{"source":71,"target":25,"value":1},
{"source":72,"target":26,"value":2},
{"source":72,"target":27,"value":1},
{"source":72,"target":11,"value":1},
{"source":73,"target":48,"value":2},
{"source":74,"target":48,"value":2},
{"source":74,"target":73,"value":3},
{"source":75,"target":69,"value":3},
{"source":75,"target":68,"value":3},
{"source":75,"target":25,"value":3},
{"source":75,"target":48,"value":1},
{"source":75,"target":41,"value":1},
{"source":75,"target":70,"value":1},
{"source":75,"target":71,"value":1},
{"source":76,"target":64,"value":1},
{"source":76,"target":65,"value":1},
{"source":76,"target":66,"value":1},
{"source":76,"target":63,"value":1},
{"source":76,"target":62,"value":1},
{"source":76,"target":48,"value":1},
{"source":76,"target":58,"value":1}
]
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment