Chartjs 2: Multi level/hierarchical category axis in chartjs - chart.js

Question

Is it possible to define a bar chart with a multi level/category axis?
For instance I'd like to display the Region/Province categories like in this Excel chart:
I found this example using multiple xAxes.
xAxes:[
{
id:'xAxis1',
type:"category",
ticks:{
callback:function(label){
var month = label.split(";")[0];
var year = label.split(";")[1];
return month;
}
}
},
{
id:'xAxis2',
type:"category",
gridLines: {
drawOnChartArea: false, // only want the grid lines for one axis to show up
},
ticks:{
callback:function(label){
var month = label.split(";")[0];
var year = label.split(";")[1];
if(month === "February"){
return year;
}else{
return "";
}
}
}
}
]
The problem is it seems that the two axes are not really linked and the alignment of second axis is based on values instead of aligning in middle of lower level category. this case cause issues
Is there a clean way to achieve this in chart.js?
Update:
I ended up creating a feature request on chartjs.

Answer 1

you can provide value separately for different axis via datesets and provide an object with different configuration option (borderColor, pointBackgroundColor, pointBorderColor) etc, i hope It'll help.
here is the link for the with an update (fiddle you shared) Updated Fiddle
data: {
labels: ["January;2015", "February;2015", "March;2015", "January;2016", "February;2016", "March;2016"],
datasets: [{
label: '# of Votes',
xAxisID:'xAxis1',
data: [12, 19, 3, 5, 2, 3]
},
// here i added another data sets for xAxisID 2 and it works just fine
{
label: '# of Potatoes',
xAxisID:'xAxis2',
data: [9, 17, 28, 26, 29, 9]
}]
}
I hope that solves your problem :)

Answer 2

Hope this helps,
I did a bit of research and couldn't find methods to implement your solution in chartjs. Chartjs has grouped bar charts but not subgrouped bar charts like in your case.
Example: http://jsfiddle.net/harshakj89/ax3zxtzw/
Here are some alternatives,
D3js (https://d3js.org/) can be used to create sub grouped bar charts.Data can be loaded from csv or json. D3 is highly configurable, but you may have to put some effort than chartsjs.
https://plnkr.co/edit/qGZ1YuyFZnVtp04bqZki?p=preview
https://stackoverflow.com/questions/37690018/d3-nested-grouped-bar-chart
https://stackoverflow.com/questions/15764698/loading-d3-js-data-from-a-simple-json-string
ZingChart is a commercial tool and can be used to implement bar charts with sub groupes.
https://www.zingchart.com/docs/chart-types/bar-charts/
But I prefer D3 over this library. because D3 comes under BSD License.

Answer 3

This should work as per your requirement http://tobiasahlin.com/blog/chartjs-charts-to-get-you-started/#8-grouped-bar-chart

Answer 4

The best library I could found to have exactly this feature is Highcharts, this is my implementation:
and here http://jsfiddle.net/fieldsure/Lr5sjh5x/2/ you can find out how to implement it.
$(function () {
var chart = new Highcharts.Chart({
chart: {
renderTo: "container",
type: "column",
borderWidth: 5,
borderColor: '#e8eaeb',
borderRadius: 0,
backgroundColor: '#f7f7f7'
},
title: {
style: {
'fontSize': '1em'
},
useHTML: true,
x: -27,
y: 8,
text: '<span class="chart-title"> Grouped Categories with 2 Series<span class="chart-href"> Black Label </span> <span class="chart-subtitle">plugin by </span></span>'
},
yAxis: [{ // Primary yAxis
labels: {
format: '${value}',
style: {
color: Highcharts.getOptions().colors[0]
}
},
title: {
text: 'Daily Tickets',
style: {
color: Highcharts.getOptions().colors[0]
}
}
}, { // Secondary yAxis
title: {
text: 'Invoices',
style: {
color: Highcharts.getOptions().colors[0]
}
},
labels: {
format: '${value}',
style: {
color: Highcharts.getOptions().colors[0]
}
},
opposite: true
}]
,
series: [{
name: 'Daily',
type: 'column',
yAxis: 1,
data: [4, 14, 18, 5, 6, 5, 14, 15, 18],
tooltip: {
valueSuffix: ' mm'
}
}, {
name: 'Invoices',
type: 'column',
data: [4, 17, 18, 8, 9, 5, 13, 15, 18],
tooltip: {
valueSuffix: ' °C'
}
}],
xAxis: {
categories: [{
name: "1/1/2014",
categories: ["Vendor 1", "Vendor 2", "Vendor 3"]
}, {
name: "1/2/2014",
categories: ["Vendor 1", "Vendor 2", "Vendor 3"]
}, {
name: "1/3/2014",
categories: ["Vendor 1", "Vendor 2", "Vendor 3"]
}]
}
});
});
body {
padding: 0px !important;
margin: 8px;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="http://code.highcharts.com/highcharts.js"></script>
<script src="http://blacklabel.github.io/grouped_categories/grouped-categories.js"></script>
<div id="container" class="chart-container"></div>
But the problem is the library is not free for commercial purposes, and this is the Chartjs implementation, in my case it is look like this:
const data ={"labels":[{"label":"Exams","children":["Wellness Examination"]},{"label":"Surgery","children":["Neuter Surgery"]},{"label":"Vaccines","children":["Bordetella"]},{"label":"Dentistry","children":["Dental Cleaning"]},{"label":"Diagnostics","children":["Other","Pre-Anesthetic","Adult Diagnostics","Pre-Anesthetic Diagnostics","Heartworm & Tick Borne Disease Test"]},{"label":"Treatments/Other","children":["Other","Microchip"]}],"datasets":[{"label":"Consumed","backgroundColor":"red","tree":[{"value":0,"children":["0"]},{"value":0,"children":["0"]},{"value":1,"children":["1"]},{"value":0,"children":["0"]},{"value":15,"children":["0","1","3","11","0"]},{"value":15,"children":["2","13"]}]},{"label":"Purchased","backgroundColor":"blue","tree":[{"value":28,"children":["28"]},{"value":1,"children":["1"]},{"value":24,"children":["24"]},{"value":10,"children":["10"]},{"value":103,"children":["2","16","34","49","2"]},{"value":165,"children":["75","90"]}]}]};
window.onload = () => {
const ctx = document.getElementById("canvas").getContext("2d");
window.myBar = new Chart(ctx, {
type: 'bar',
data: data,
options: {
responsive: true,
title: {
display: true,
text: 'Chart.js Hierarchical Bar Chart'
},
layout: {
padding: {
// add more space at the bottom for the hierarchy
bottom: 45
}
},
scales: {
xAxes: [{
type: 'hierarchical',
stacked: false,
// offset settings, for centering the categorical
//axis in the bar chart case
offset: true,
// grid line settings
gridLines: {
offsetGridLines: true
}
}],
yAxes: [{
stacked: false,
ticks: {
beginAtZero: true
}
}]
}
}
});
};
canvas {
-moz-user-select: none;
-webkit-user-select: none;
-ms-user-select: none;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://unpkg.com/chart.js/dist/Chart.bundle.js"></script>
<script src="https://unpkg.com/chartjs-scale-hierarchical"></script>
<div id="container" style="width: 75%;">
<canvas id="canvas"></canvas>
</div>
for each more column just add another dataset.