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@guilhermesimoes
Last active Apr 5, 2020
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D3.js: Animating between scales

The purpose of this gist is two-fold:

  1. Demonstrate how to animate between scales;

  2. Show how data visualization depends on the chosen scale.

    For example, we can see how some data clusters using the power scale. The datums 1 and 10 are rendered on the same spot. If we had a lot of these points close to each other and performance was a concern, filtering out some of these points could prove valuable.

<!DOCTYPE html>
<meta charset="utf-8">
<style>
html, body {
height: 100%;
margin: 0;
}
.chart-container {
position: relative;
box-sizing: border-box;
height: 100%;
padding: 15px;
font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
}
.chart-container .controls {
position: absolute;
top: 15px;
left: 15px;
}
.chart {
width: 100%;
height: 100%;
overflow: visible;
}
.chart path,
.chart line,
.chart rect {
shape-rendering: crispEdges;
}
.chart .axis path,
.chart .axis line {
fill: none;
stroke: #000;
}
.chart .linear .point {
fill: steelblue;
}
.chart .pow .point {
fill: #CD4638;
}
</style>
<body>
<div class="chart-container js-chart-container">
<form class="controls">
Scale:
<label><input type="radio" name="x-scale" value="power2" checked>Power2</label>
<label><input type="radio" name="x-scale" value="linear">Linear</label>
<label><input type="radio" name="x-scale" value="sqrt">SquareRoot</label>
<label><input type="radio" name="x-scale" value="log2">Log2</label>
<label><input type="radio" name="x-scale" value="log10">Log10</label>
</form>
<svg class="chart js-chart"></svg>
</div>
<script src="https://d3js.org/d3.v5.min.js"></script>
<script type="text/javascript">
"use strict";
/* global d3, document */
var chart = {
margin: { top: 0, right: 25, bottom: 0, left: 25 },
animationDuration: 400,
scales: {
power2: d3.scalePow().exponent(2),
linear: d3.scaleLinear(),
sqrt: d3.scalePow().exponent(0.5),
log2: d3.scaleLog().base(2),
log10: d3.scaleLog().base(10)
},
init: function (options, data) {
this.el = d3.select(".js-chart")
.attr("viewBox", "0 0 " + options.width + " " + options.height);
this.width = options.width - this.margin.left - this.margin.right;
this.height = options.height - this.margin.top - this.margin.bottom;
this.adaptScales();
this.setXScale();
this.draw(data);
d3.selectAll(".js-chart-container input").on("click", this.changeXScale.bind(this));
},
draw: function (data) {
var mainGroup, series;
mainGroup = this.el.append("g")
.attr("transform", "translate(" + this.margin.left + "," + this.margin.top + ")");
series = mainGroup.selectAll(".series").data(data)
.enter().append("g")
.attr("class", function (d) { return "series " + d.name; });
this.points = series.selectAll(".point").data(function (d) { return d.points; })
.enter().append("circle")
.attr("class", "point")
.attr("cx", this.xScale)
.attr("cy", this.height / 3)
.attr("r", 6);
this.points.append("title")
.text(String);
this.xAxis = d3.axisBottom()
.scale(this.xScale);
this.domXAxis = mainGroup.append("g")
.attr("class", "axis axis--x")
.attr("transform", "translate(0," + this.height / 2 + ")")
.call(this.xAxis);
},
redraw: function () {
this.domXAxis.transition()
.duration(this.animationDuration)
.call(this.xAxis.scale(this.xScale));
this.points.transition()
.duration(this.animationDuration)
.attr("cx", this.xScale);
},
adaptScales: function () {
Object.keys(this.scales).forEach(function (scaleType) {
this.scales[scaleType]
.domain([1, 1000])
.range([0, this.width]);
}, this);
},
changeXScale: function () {
this.setXScale();
this.redraw();
},
setXScale: function () {
var scaleType;
scaleType = d3.select(".js-chart-container input:checked").node().value;
this.xScale = this.scales[scaleType];
}
};
var options = {
width: 800,
height: 400
};
var data = [
{
name: "linear",
points: [300, 400, 500, 600]
},
{
name: "pow",
points: [1, 10, 100, 1000]
}
];
chart.init(options, data);
</script>
</body>
@guillaumechaumet
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guillaumechaumet commented Jun 26, 2017

HiI @guilhermesimoes
I try to make a two axes version of your nice piece of code. here: https://jsfiddle.net/hL4x15u0/11/
I bumped on the cx cy (scaled) version with NaN values. Did you have a tip?
Cheers

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