I have been struggling to make a chart.js line chart start at 0 when all of the values are 0. If all of the data of a dataset is 0 the y axis will always show values below 0 which I don't want there.
Here is the example:
<div class="container">
<canvas id="lineChart"></canvas>
<script>
var ctx = document.getElementById('lineChart');
var lineChart = new Chart(ctx, {
type: 'line',
data: {
labels: [1,2,3],
datasets: [{
data: [0, 0, 0]
}]
},
options: {
responsive: true,
scales: {
y: {
ticks: {
beginAtZero:true
}
}
}
}
});
</script>
<div>
As you can see I am changing the options the scales as suggested in the documentation here (apparently there has been migration and this is the way to go in v3, which is what I am using). But the graph still won't start at 0:
Any axis options other than the ticks work correctly.
Any ideas of what I might be doing wrong?
You tried to place the beginAtZero in the V2 place, in V3 you have to put it in the root of the scale object like so:
const options = {
type: 'line',
data: {
labels: [1, 2, 3],
datasets: [{
label: '# of Votes',
data: [0, 0, 0],
borderColor: 'pink'
}]
},
options: {
scales: {
y: {
beginAtZero: true
}
}
}
}
const ctx = document.getElementById('chartJSContainer').getContext('2d');
new Chart(ctx, options);
<body>
<canvas id="chartJSContainer" width="600" height="400"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.7.0/chart.js"></script>
</body>
For all changes between V2 and V3 you can read the migration guide
Related
I am using chart.js for my project. As you can see in the following code, chart.js uses different minimum and maximum values for y-axis for line and bar graphs for same data. In the given code, 1100-1700 is the value range for line graph whereas 0-2000 is the value range used for bar graph.
I like to make same minimum and maximum values for both line and bar graphs. One option is to find minimum, maximum and step-size values my own and use the properties min, max and ticks.stepSize under scales. But finding minimum, maximum and step-size for a given data data is a serious task.
For my requirement, default minimum ,maximum and stepSize used by chart.js for line graph is fine and I would like to use the same values for bar graph also.
I could first render line graph, get these values from this graph (like scales.y.min) and then use it for bar graph, which is perfectly working
Is there a way I could get the default min, max, stepSize values used by chart.js for line graph before actually drawing the graph? Any answers or pointers are really appreciated. Thanks
var chart1 = new Chart(document.getElementById('chart1'),
{
type: 'line',
data:
{
labels: ['a','b','c'],
datasets:
[
{
label: 'A',
data: [1212,1122, 1188, 1617, 1116],
borderColor: 'green',
}
]
}
});
var chart2 = new Chart(document.getElementById('chart2'),
{
type: 'bar',
data:
{
labels: ['a','b','c'],
datasets:
[
{
label: 'A',
data: [1212,1122, 1188, 1617, 1116],
backgroundColor: 'green',
}
]
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.9.1/chart.min.js"></script>
<div style="width:300px;height:200px"><canvas id="chart1"></canvas></div>
<div style="width:300px;height:200px"><canvas id="chart2"></canvas></div>
The first thing you could do is to set beginAtZero to false to Y axis of bar chart because is set to true by default:
https://github.com/chartjs/Chart.js/blob/v3.9.1/src/controllers/controller.bar.js#L636-L650
Then you can set the same scale config to both charts.
options: { // options of charts
scales: {
y: {
beginAtZero: false,
}
}
}
var chart1 = new Chart(document.getElementById('myChart1'),
{
type: 'line',
data:
{
labels: ['a','b','c'],
datasets:
[
{
label: 'A',
data: [1212,1122, 1188, 1617, 1116],
borderColor: 'green',
}
]
},
options: {
scales: {
y: {
beginAtZero: false,
}
}
}
});
var chart2 = new Chart(document.getElementById('myChart2'),
{
type: 'bar',
data:
{
labels: ['a','b','c'],
datasets:
[
{
label: 'A',
data: [1212,1122, 1188, 1617, 1116],
backgroundColor: 'green',
}
]
},
options: {
scales: {
y: {
beginAtZero: false,
}
}
}
});
.myChartDiv {
max-width: 300px;
max-height: 200px;
}
<script src="https://cdn.jsdelivr.net/npm/chart.js#3.9.1/dist/chart.min.js"></script>
<html>
<body>
<div class="myChartDiv">
<canvas id="myChart1" width="300" height="200"/>
</div>
<div class="myChartDiv">
<canvas id="myChart2" width="300" height="200"/>
</div>
</body>
</html>
I am using chart.js to develop a TreeMap. It works great but the issue is each rectangle only shows the value of the data. I want to add some custom text next to the value. How do I achieve this?
var topTags = [
{tag:'python',num:133269},{tag:'javascript',num:109742},{tag:'java',num:65490},{tag:'c#',num:45445},{tag:'html',num:43767},{tag:'android',num:42657},{tag:'reactjs',num:38844},{tag:'php',num:34381},{tag:'sql',num:29996},{tag:'python',num:29942},{tag:'css',num:29654},{tag:'r',num:28319},{tag:'c++',num:27389},{tag:'node.js',num:25415},{tag:'angular',num:24093},{tag:'pandas',num:23826},{tag:'arrays',num:23075},{tag:'jquery',num:18968},{tag:'mysql',num:18863},{tag:'swift',num:17971},{tag:'ios',num:17600},{tag:'json',num:15589},{tag:'laravel',num:15537},{tag:'flutter',num:15201},{tag:'c',num:15195},{tag:'django',num:14748},{tag:'sql',num:12752},{tag:'reactjs',num:10974},{tag:'excel',num:10962},{tag:'list',num:10726},{tag:'regex',num:10676}
];
var canvas = document.getElementById("treemap");
var ctx = canvas.getContext("2d");
var chart = window.chart = new Chart(ctx, {
type: "treemap",
data: {
datasets: [{
tree: topTags,
key: "num",
groups: ['num'],
spacing: 0.5,
borderWidth: 1.5,
fontColor: "black",
borderColor: "grey"
}]
},
options: {
maintainAspectRatio: false,
legend: { display: false },
tooltips: { enabled: false }
}
});
When running this code, I get the numbers in each rectangle but I need some text to be appended next to the numbers for each rectangle. How do I achieve this?
You can use the formatter options in the labels section:
const options = {
type: 'treemap',
data: {
datasets: [{
label: '# of Votes',
tree: [12, 19, 3, 5, 2, 3],
backgroundColor: 'pink',
labels: {
display: true,
formatter(ctx) {
const data = ctx.chart.data;
return `Custom Text: ${data.datasets[ctx.datasetIndex].tree[ctx.dataIndex]}`;
}
},
}]
},
options: {}
}
const ctx = document.getElementById('chartJSContainer').getContext('2d');
new Chart(ctx, options);
<body>
<canvas id="chartJSContainer" width="600" height="400"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.7.0/chart.js"></script>
<script src="https://cdn.jsdelivr.net/npm/chartjs-chart-treemap#2.0.1/dist/chartjs-chart-treemap.js"></script>
</body>
I am trying to personalize a chart.js. But I can not find how to remove (or hide) the X and Y axes.
I am also interested in not showing data on hover and I would like not to show the reference on the top. I am just starting with chart.js and I only need to do a few graphs.
Thank you :)
This is the graph I currently have
datasets: {
label: "I need help plz",
backgroundColor: gradient,
fill: true,
borderColor: "rgb(0, 50, 100)",
borderWidth: 0.001,
tension: 0.4,
radius: 0,
data: dataset,
},
For removing the references on the top this post was useful Chart.js v2 hide dataset labels
As described in the documentation (https://www.chartjs.org/docs/master/axes/#common-options-to-all-axes) you can set in the options of the scale the display to true or false or 'auto' where auto hides the scale if no dataset is visable that is linked to that axis.
For not showing data on hover you can set the tooltip to enabled: false
Example (y auto display and no x axis):
var options = {
type: 'bar',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
borderWidth: 1,
backgroundColor: 'red'
}, ]
},
options: {
plugins: {
tooltip: {
enabled: false
}
},
scales: {
y: {
display: 'auto'
},
x: {
display: false
}
}
}
}
var ctx = document.getElementById('chartJSContainer').getContext('2d');
new Chart(ctx, options);
<body>
<canvas id="chartJSContainer" width="600" height="400"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.3.2/chart.js"></script>
</body>
I am having an scenario, where I need to show the slice value inside of the slice in pie chart. I am having more than 1 pie charts on my webpage. Below code is perfectly working but only for 1st Pie Chart and for others its throwing error as below, could you please help me to sort this out?
Error:: unCaught TypeError: cannot read the property 'data' of undefined.
Code::
options:{
animation:{
onComplete:function(){
var ctx = this.chart.ctx;
var dataset_obj = this.data.datasets;
for (var i=0;i<dataset_obj.length; i++){
var meta_obj = dataset_obj[i]._meta[i].data;
for (var j=0; j<meta_obj.length; j++){
var model =meta_obj[j]._model;
start_angle= model.startAngle;
end_angle = model.endAngle;
mid_angle =start_angle + ( end_angle -start_angle)/2;
mid_radius = model.innerRadius + (model.outerRadius -model.innerRadius)/2;
var x =mid_radius*math.cos(mid_angle);
var y = mid_radius*math.cos(mid_angle);
ctx.fillstyle='#fff';
if (dataset_obj[i].data[j] != 0 && meta_obj[j].hidden != true){
ctx.fillText(dataset_obj[i].data[j], model.x+x, model.y+y);
}
}
}
}
}
}
This answers the issue contained in the question's title:
How to show slice value inside of slice in pie chart using chart.js
The code snippet below show how to display the values inside the slices with the use of chartjs-plugin-labels. The code of the samples was extracted from the chartjs-plugin-labels demo page.
var canvas = document.getElementById('myChart');
new Chart(canvas, {
type: 'pie',
data: {
labels: ['January', 'February', 'March'],
datasets: [{
data: [50445, 33655, 15900],
backgroundColor: ['#FF6384', '#36A2EB','#FFCE56']
}]
},
options: {
responsive: true,
maintainAspectRatio: true,
plugins: {
labels: {
render: 'value',
fontColor: ['green', 'white', 'red']
}
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.min.js"></script>
<script src="https://cdn.jsdelivr.net/gh/emn178/chartjs-plugin-labels/src/chartjs-plugin-labels.js"></script>
<canvas id="myChart"></canvas>
If you want to display the percentage of each slice, you can do the following:
var canvas = document.getElementById('myChart');
new Chart(canvas, {
type: 'pie',
data: {
labels: ['January', 'February', 'March'],
datasets: [{
data: [50445, 33655, 15900],
backgroundColor: ['#FF6384', '#36A2EB','#FFCE56']
}]
},
options: {
responsive: true,
maintainAspectRatio: true,
plugins: {
labels: {
render: 'percentage',
fontColor: ['green', 'white', 'red'],
precision: 2
}
},
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.min.js"></script>
<script src="https://cdn.jsdelivr.net/gh/emn178/chartjs-plugin-labels/src/chartjs-plugin-labels.js"></script>
<canvas id="myChart"></canvas>
Just wondering if there is any way to set the horizontal bar labels for y-axis using chart.js. Here is how I set up the chart:
<div class="box-body">
<canvas id="chart" style="position: relative; height: 300px;"></canvas>
</div>
Javascript:
var ctx = document.getElementById('chart').getContext("2d");
var options = {
layout: {
padding: {
top: 5,
}
},
responsive: true,
animation: {
animateScale: true,
animateRotate: true
},
};
var opt = {
type: "horizontalBar",
data: {
labels: label,
datasets: [{
data: price,
}]
},
options: options
};
if (chart) chart.destroy();
chart= new Chart(ctx, opt);
chart.update();
As you all can see, the first and third labels are too long and cut off. Is there a way to make the label multi-line?
If you want to have full control over how long labels are broken down across lines you can specify the breaking point by providing labels in a nested array. For example:
var chart = new Chart(ctx, {
...
data: {
labels: [["Label1 Line1:","Label1 Line2"],["Label2 Line1","Label2 Line2"]],
datasets: [{
...
});
You can use the following chart plugin :
plugins: [{
beforeInit: function(chart) {
chart.data.labels.forEach(function(e, i, a) {
if (/\n/.test(e)) {
a[i] = e.split(/\n/);
}
});
}
}]
add this followed by your chart options
ᴜꜱᴀɢᴇ :
add a new line character (\n) to your label, wherever you wish to add a line break.
ᴅᴇᴍᴏ
var chart = new Chart(ctx, {
type: 'horizontalBar',
data: {
labels: ['Jan\n2017', 'Feb', 'Mar', 'Apr'],
datasets: [{
label: 'BAR',
data: [1, 2, 3, 4],
backgroundColor: 'rgba(0, 119, 290, 0.7)'
}]
},
options: {
scales: {
xAxes: [{
ticks: {
beginAtZero: true
}
}]
}
},
plugins: [{
beforeInit: function(chart) {
chart.data.labels.forEach(function(e, i, a) {
if (/\n/.test(e)) {
a[i] = e.split(/\n/);
}
});
}
}]
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.min.js"></script>
<canvas id="ctx"></canvas>