We Keep Coding

Chart.js : How I change the x axes ticks labels alignment in any sizes?

How can I move my labels on my x axes in between another x axes label. Nothing seems to work and I was unable to find anything on the docs. Is there a workaround? I'm using line chart time series.
https://www.chartjs.org/samples/latest/scales/time/financial.html
Currently, with the code I have its generating the figure below:
var cfg = {
elements:{
point: {
radius: 4
}
},
data: {
datasets: [
{
label: 'vsy',
backgroundColor: color(window.chartColors.red).alpha(0.5).rgbString(),
borderColor: window.chartColors.red,
data: firstData,
type: 'line',
pointRadius: 2,
fill: false,
lineTension: 0,
borderWidth: 2
},
{
label: 'de vsy',
backgroundColor: color(window.chartColors.blue).alpha(0.5).rgbString(),
borderColor: window.chartColors.blue,
data: dataMaker(15),
type: 'line',
pointRadius: 2,
fill: false,
lineTension: 0,
borderWidth: 2
}
],
},
options: {
animation: {
duration: 0
},
scales: {
xAxes: [{
type: 'time',
distribution: 'series',
offset: true,
time: {
unit: 'month',
displayFormats: {
month: 'MMM'
}
},
ticks: {
autoSkip: true,
autoSkipPadding: 75,
sampleSize: 100
},
}],
yAxes: [{
gridLines: {
drawBorder: false
}
}]
},
tooltips: {
intersect: false,
mode: 'index',
}
}
};
This is what I have now:
I want the labels on the x-axis to be on center instead of below the y axis grid line.
Thanks to uminder, with his comment it solves the issue but now I have a conflicting tooltip which lie on a same grid. When I hover to april line first point it shows me mar 30 which lies just above it and vice versa.
I fixed it by changing the mode to nearest but why is it activating the another point?

The option you're looking for is offsetGridLines.
If true, grid lines will be shifted to be between labels.
xAxes: [{
...
gridLines: {
offsetGridLines: true
}
In most cases, this produces the expected result. Unfortunately it doesn't work for time axes as documented in Chart.js issue #403. Thanks to Antti Hukkanen, there exists a workaround.
Please have a look at below runnable code snippet to see how it works.
function generateData() {
var unit = 'day';
function randomNumber(min, max) {
return Math.random() * (max - min) + min;
}
function randomPoint(date, lastClose) {
var open = randomNumber(lastClose * 0.95, lastClose * 1.05).toFixed(2);
var close = randomNumber(open * 0.95, open * 1.05).toFixed(2);
return {
t: date.valueOf(),
y: close
};
}
var date = moment().subtract(1, 'years');
var now = moment();
var data = [];
for (; data.length < 600 && date.isBefore(now); date = date.clone().add(1, unit).startOf(unit)) {
data.push(randomPoint(date, data.length > 0 ? data[data.length - 1].y : 30));
}
return data;
}
var TimeCenterScale = Chart.scaleService.getScaleConstructor('time').extend({
getPixelForTick: function(index) {
var ticks = this.getTicks();
if (index < 0 || index >= ticks.length) {
return null;
}
// Get the pixel value for the current tick.
var px = this.getPixelForOffset(ticks[index].value);
// Get the next tick's pixel value.
var nextPx = this.right;
var nextTick = ticks[index + 1];
if (nextTick) {
nextPx = this.getPixelForOffset(nextTick.value);
}
// Align the labels in the middle of the current and next tick.
return px + (nextPx - px) / 2;
},
});
// Register the scale type
var defaults = Chart.scaleService.getScaleDefaults('time');
Chart.scaleService.registerScaleType('timecenter', TimeCenterScale, defaults);
var cfg = {
data: {
datasets: [{
label: 'CHRT - Chart.js Corporation',
backgroundColor: 'red',
borderColor: 'red',
data: generateData(),
type: 'line',
pointRadius: 0,
fill: false,
lineTension: 0,
borderWidth: 2
}]
},
options: {
animation: {
duration: 0
},
scales: {
xAxes: [{
type: 'timecenter',
time: {
unit: 'month',
stepSize: 1,
displayFormats: {
month: 'MMM'
}
},
gridLines: {
offsetGridLines: true
}
}],
yAxes: [{
gridLines: {
drawBorder: false
}
}]
},
tooltips: {
intersect: false,
mode: 'index'
}
}
};
var chart = new Chart('chart1', cfg);
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.18.1/moment.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.min.js"></script>
<canvas id="chart1" height="90"></canvas>

For chartJs v3 you can use offset property:
scales: {
x: {
grid: {
offset: true
}
},
...
}

How do I use the return values from csv ajax request for x and y values?

I am trying to import a csv file and use it as the data source for my scatter chart in ChartJs. When I print dataPoints I get object arrays of the correct value so I know the ajax request is pulling properly. But I cant seem to pass these values into my datasets data as x and y values.
I was able to successfully pull the data and plug it into x and y values using canvasJS unfortunately that framework isn't free so I am trying to switch to chart.js. Ive tried plugging in data: [{dataPoints: pullData()}] or data: pullData() or data: [dataPoints] and plenty of other combinations but none seem to work. I am familiar with coding in swift and java but I'm particularly new to Javascript. Any help would be greatly appreciated!
const CHART = document.getElementById("scatterChart");
console.log(CHART);
var scatterChart = new Chart(CHART, {
type: 'scatter',
data: {
datasets: [{
label: 'Scatter Dataset',
data: [{
x: -10,
y: 0
}, {
x: 0,
y: 10
}, {
x: 10,
y: 5
}],
borderColor: 'black',
borderWidth: 1,
pointBackgroundColor: '#00bcd6',
pointRadius: 5,
pointHoverRadius: 5,
fill: false,
tension: 0.5,
showLine: true
}]
},
options: {
scales: {
xAxes: [{
type: 'linear',
position: 'bottom'
}],
yAxes: [{
type: 'linear',
position: 'left'
}]
}
}
});
window.onload = function(){
$.ajax({
type: "GET",
url: "mockData.csv",
dataType: "text",
success: function (result){
var data = $.csv.toArrays(result);
var dataPoints = [];
for (var i = 0; i < data.length; i++)
dataPoints.push({
x: data[i][0],
y: data[i][1]
});
console.log(dataPoints)
return dataPoints
}
})
};
My goal is to plot the points from the csv (which is just 5 rows and 2 columns of basic numbers) but instead no points show up. Where as when I hand jam the values into x and y everything shows up fine.

You need to move the creation of the chart to inside the success function of the ajax call, or pass dataPoints into some other function that creates the chart.

After #terpinmd suggestion I was able to resolve the problem. Below is the code solution:
function getDataPointsFromCSV(csv) {
var dataPoints = csvLines = points = [];
for (var i = 0; i < csv.length; i++)
dataPoints.push({
x: csv[i][0],
y: csv[i][1]
});
console.log(dataPoints)
return dataPoints
}
window.onload = function(){
var dataPoints = [];
$.ajax({
type: "GET",
url: "mockData.csv",
dataType: "text",
success: function (result){
var data = $.csv.toArrays(result);
const CHART = document.getElementById("scatterChart");
console.log(CHART);
var scatterChart = new Chart(CHART, {
type: 'scatter',
data: {
datasets: [{
label: 'Scatter Dataset',
data: getDataPointsFromCSV(data),
borderColor: 'black',
borderWidth: 1,
pointBackgroundColor: '#00bcd6',
pointRadius: 5,
pointHoverRadius: 5,
fill: false,
tension: 0.5,
showLine: true
}]
},
options: {
scales: {
xAxes: [{
type: 'linear',
position: 'bottom'
}],
yAxes: [{
type: 'linear',
position: 'left'
}]
}
}
});
}
})
};

ChartJs Bubble chart - on hover bubble becomes too big

I created a bubble chart using ChartJs and populating data dynamically using Json.
See the code below.
for (var i = 0; i < response.data.length; i++) {
var point_data = [];
point_data.push({
x: response.data[i]['return_tickets'].toString(),
y: Math.round(response.data[i]['return_percentage']).toString(),
r: Math.round((response.data[i]['return_percentage'])).toString()
});
data.push({ label: response.data[i]['staff_name'], data: point_data, backgroundColor: getRandomColor(), hoverRadius:4 });
}
new Chart(document.getElementById("bubbleChart"), {
type: 'bubble',
data: {
datasets: data
},
options: {
title: {
display: true,
text: ''
}, scales: {
yAxes: [{
scaleLabel: {
display: true,
labelString: "Return Tickets %"
}
}],
xAxes: [{
scaleLabel: {
display: true,
labelString: "Return Tickets"
}
}]
}
}
});
It generates the desired chart as below
The problem is when I hover over any bubble the size of the bubble increases exponentially.
How to keep the size same ?
I'm setting the hoverRadius property of the dataset but it does nothing for me.

Problem is with your this line of code:
{ label: response.data[i]['staff_name'], data: point_data, backgroundColor: getRandomColor(), hoverRadius:4 }
This is not a valid JSON. Values must be either strings or arrays. Most probably issue is at label: response.data[i]['staff_name'] or in point_data (I can see you are making x, y and r values .toString() that maybe not required). Check it again. Create a valid JSON and then try by setting hoverRadius: 0, it will work.
Setting hoverRadius: 0 working fine for me. Bubble size will not change on mouse over if you set hoverRadius: 0.
Below is working example:
var chart = new Chart(ctx, {
type: 'bubble',
data: {
datasets: [{
label: 'Bubble',
data: [{
x: 5,
y: 55,
r: 27.5
}],
backgroundColor: 'rgba(0, 119, 290, 0.6)',
hoverRadius: 0
}]
},
options: {
tooltips: {
callbacks: {
label: function(t, d) {
return d.datasets[t.datasetIndex].label +
': (Day:' + t.xLabel + ', Total:' + t.yLabel + ')';
}
}
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.2/Chart.min.js"></script>
<canvas id="ctx"></canvas>
Checkout official documentation for more info : https://www.chartjs.org/docs/latest/charts/bubble.html#dataset-properties

I have already faced the same issue also fixed it by typecasting for every x,y & z. I just convert it to float
'x' => (float) $x_axis_value,
'y' => (float) $y_axis_value,
'r' => (float) $radious_value,

Add Data Labels onto a bubble chart on chart.js

I have used a Bubble Chart on Chart.js to create sliders to show comparable performance and they currently look a bit like this:
What am I trying to do
I want to add data labels just above / in my 'bubbles' with my values in. Much like the '10' you can see on each bubble here.
What have I done to achieve this
This is not standard Chart.js functionality but I found this post which was discussing a similar issue for bar / line charts.
I've installed the plugin that post suggested but the data label it shows is for the radius of the bubble and I want to it to be the x-axis of the bubble.
I've also tried to use the code from some of the answers on that post, but with absolutely no luck.
My Code
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.0/Chart.bundle.js"></script>
<script src="https://cdn.jsdelivr.net/npm/chartjs-plugin-datalabels"></script>
<div class="container" >
<h2>Chart.js — Line Chart Demo</h2>
<div>
<canvas id="myChart"></canvas>
</div>
</div>
<script>
var ctx = document.getElementById('myChart').getContext('2d');
ctx.height = 1000;
var myChart = new Chart(ctx, {
type: 'bubble',
data: {
datasets: [
{
label: 'Your Data',
data: [
{x: 78.7, y: 0, r: 10, name: "Performance"}
],
backgroundColor: "rgba(153,255,51,0.6)"
},
{
label: 'Average',
data: [
{x: 100.7, y: 0, r: 10, name: "Performance"} // The labe needs to be X. not R.
],
backgroundColor: "rgba(255,0,128,0.6)"
}
]
},
options: {
maintainAspectRatio: false,
scales: {
yAxes: [{
id: 'first-y-axis',
type: 'linear',
ticks: {
min: 0,
max: 1,
stepSize: 1,
display: false
},
gridLines: {
display: false,
drawBorder: false
}
}],
xAxes: [{
ticks: {
min: 50, // Controls where axis starts
max: 120 // Controls where axis finishes
},
gridLines: {
display: false,
lineWidth: 3 // Width of bottom line
}
}]
}
}
});
</script>
Thanks in advance

I've managed to find the answer to this question, basically by taking apart the bubble chart example from the chartjs-plugin-datalabels plugin.
Below is a working example. Pay attention to the section in options that says 'plugin'.
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.0/Chart.bundle.js"></script>
<script src="https://cdn.jsdelivr.net/npm/chartjs-plugin-datalabels"></script>
<div class="container" >
<h2>Chart.js — Line Chart Demo</h2>
<div>
<canvas id="myChart"></canvas>
</div>
</div>
<script>
var ctx = document.getElementById('myChart').getContext('2d');
ctx.height = 1000;
var myChart = new Chart(ctx, {
type: 'bubble',
data: {
datasets: [
{
label: 'Your Data',
data: [
{x: 78.7, y: 0, r: 10, name: "Performance"}
],
backgroundColor: "rgba(153,255,51,0.6)"
},
{
label: 'Average',
data: [
{x: 100.7, y: 0, r: 10, name: "Performance"} // The labe needs to be
],
backgroundColor: "rgba(255,0,128,0.6)"
}
]
},
options: {
plugins: { // Look at this bit
datalabels: {
anchor: function(context) {
var value = context.dataset.data[context.dataIndex];
return value.x < 50 ? 'end' : 'center';
},
align: function(context) {
var value = context.dataset.data[context.dataIndex];
return value.x < 50 ? 'end' : 'center';
},
color: function(context) {
var value = context.dataset.data[context.dataIndex];
return value.x < 50 ? context.dataset.backgroundColor : 'white';
},
font: {
weight: 'bold'
},
formatter: function(value) {
return Math.round(value.x);
},
offset: 2,
padding: 0
}
},
maintainAspectRatio: false,
scales: {
yAxes: [{
id: 'first-y-axis',
type: 'linear',
ticks: {
min: 0,
max: 1,
stepSize: 1,
display: false
},
gridLines: {
display: false,
drawBorder: false
}
}],
xAxes: [{
ticks: {
min: 50, // Controls where axis starts
max: 120 // Controls where axis finishes
},
gridLines: {
display: false,
lineWidth: 3 // Width of bottom line
}
}]
}
}
});
</script>

If all you want to do is changing the label, there is an easier solution. From the docs of chartjs-plugin-datalabels:
Data values are converted to string ('' + value). If value is an object, the following rules apply first:
value = value.label if defined and not null
else value = value.r if defined and not null
else value = 'key[0]: value[key[0]], key[1]: value[key[1]], ...'
Therefore, it is sufficient to specify a label in your data points:
data: [{ x: 78.7, y: 0, r: 10, name: "Performance", label: `${Math.round(x)}` }],

How to show gradient vertically on chart js grouped bar chart?

I am using Chart.js grouped bar chart. I want to show my bars with gradient colors. Currently it show as shown in below image. Any help will be greatly appreciated.
var rateOfReturn= document.getElementById("rateofreturn-chart-canvas").getContext('2d');
var rateOfReturnData = {
labels: ["Monthly", "Quarterly", "Semiannually", "Annually"],
datasets: [
{
label: "label1",
backgroundColor: [
'#26343b',
'#26343b',
'#26343b',
'#26343b'
],
data: [4, 6, 8, -3],
},
{
label: "",
backgroundColor: [
'#be1a33',
'#be1a33',
'#be1a33',
'#be1a33'
],
data: [6, 10, 11, 7],
},
{
label: "",
backgroundColor: [
'#00b786',
'#00b786',
'#00b786',
'#00b786'
],
data: [13, 10, 9, 4],
},
{
label: "",
backgroundColor: [
'#f86929',
'#f86929',
'#f86929',
'#f86929'
],
data: [6, 8, 2, 11],
},
{
label: "",
backgroundColor: [
'#046cd0',
'#046cd0',
'#046cd0',
'#046cd0'
],
data: [4, 8, 7, 13],
}
]
};
rateOfReturn.canvas.height = 80;
var myBarChart = new Chart(rateOfReturn, {
type: 'bar',
data: rateOfReturnData,
options: {
legend:
{
display: false
},
scales:
{
xAxes: [{
title: "Test title",
ticks: {
beginAtZero: true,
titleFontWeight: "bold"
},
}],
yAxes: [{
scaleLabel: {
display: true,
labelString: 'Rate Of Return (ROR) % '
},
ticks: {
beginAtZero:true,
mirror:false,
suggestedMin: 0
},
}]
}
}
});

You want to use Chart.js plugins. They let you handle some events triggered through the chart creation such as the initialization, the resize, etc.
Chart.pluginService.register({
beforeUpdate: function(chart) {
// All the code added here will be executed before a chart update
}
});
You also want to use createLinearGradient to create a gradient color usable in a canvas :
var gradient = ctx.createLinearGradient(0,0,200,0); // Dimensions of the color rectangle
gradient.addColorStop(0,"green"); // First color
gradient.addColorStop(1,"white"); // Second color
Now you want to use both into one. Let's first see how it works.
You first have to add the two colors of the gradient you want to see in your chart data :
datasets: [{
label: "label1",
backgroundColor: [
['#26343b', 'white'], // `white` and `#FFFFFF` both stand for a white color
['#26343b', 'white'],
['#26343b', 'white'],
['#26343b', 'white']
],
data: [4, 6, 8, -3],
}, {
// ...
}]
Then you need to add the following plugin before you create the chart (using new Chart()), or else it won't be added into the chart's plugin service :
Chart.pluginService.register({
beforeUpdate: function(chart) {
// For every dataset ...
for (var i = 0; i < chart.config.data.datasets.length; i++) {
// We store it
var dataset = chart.config.data.datasets[i];
// For every data in this dataset
for (var j = 0; j < dataset.data.length; j++) {
// We store the data model (graph information)
var model = dataset._meta[0].data[j]._model;
// We use the model to get the left & right borders X position
// and to create the gradient
var start = model.x,
end = model.x + model.width,
gradient = rateOfReturn.createLinearGradient(start, 0, end - 5, 0);
// The colors of the gradient that were defined in the data
gradient.addColorStop(0, dataset.backgroundColor[j][0]);
gradient.addColorStop(1, dataset.backgroundColor[j][1]);
// We set this new color to the data background
dataset.backgroundColor[j] = gradient;
}
}
}
});
Follows the result of the plugin with your example, which you can find on this jsFiddle :