How to show Charts.js lables - chart.js

How to show the above lables in charts.js?

You can find it in the Charts.js documentation but this is a working polar chart. Just need to create your canvas in the body of the html and reference it correctly. Changing labels: is where you will change the top part that you are requesting.
var ctx = document.getElementById("myChart").getContext('2d');
var myChart = new Chart(ctx, {
type: 'polarArea',
responsive: false,
data: {
labels: ["Red", "Green", "Yellow", "Grey", "Blue"],
datasets: [{
backgroundColor: [
"red",
"green",
"yellow",
"grey",
"blue"
],
data: [12, 19, 3, 17, 28]
}]
}
});

Related

How to change line segment color based on label value in chart.js?

There is an example of how to change line segment color based on point value, with a function like this
borderColor: function(context) {
if (context.p0.parsed.y == 5){
return 'transparent';
}
},
I want to set the color based on the value of the label. This doesn't work:
context.p0.parsed.x == 'February'
With the new verion of chart.js that released today (3.6.0) you can access the chart object and you get the dataIndex so you can check it in the labels array like so:
const options = {
type: 'line',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
segment: {
borderColor: (ctx) => (ctx.chart.data.labels[ctx.p0DataIndex] === "Green" ? "Pink" : "Orange")
}
}]
},
options: {}
}
const ctx = document.getElementById('chartJSContainer').getContext('2d');
new Chart(ctx, options);
<body>
<canvas id="chartJSContainer" width="600" height="400"></canvas>
<script src="https://cdn.jsdelivr.net/npm/chart.js#3.6.0/dist/chart.min.js"></script>
</body>

How to get chart size (without labels) with chart.js?

Now i have this chart:
https://codepen.io/UnluckySerivelha/pen/BawpPYv
const ctx = document.getElementById('graph').getContext('2d');
var bar_ctx = document.getElementById('graph').getContext('2d');
x=["14 Dec","15 Dec"];
y1={"14 Dec":0,"15 Dec":0,};
y2={"14 Dec":0,"15 Dec":0,};
const myChart = new Chart(ctx, {
type: 'bar',
data: {
labels: x,
datasets: [
{
label: 'Всего за день',
data: y1
},
{
label: 'Будет начислено по вкладам',
data: y2,
},
]
},
options: {
scales: {
y: {
beginAtZero: true,
ticks: {
callback: function(value, index, values) {
return '$ ' + value;
}
}
}
},
responsive: true,
maintainAspectRatio: false
},
});
I want to add background image for chart area, but not for labels. I know how to add background image, but don't know how to get size of chart area without labels for assignment size and position of image. Is it possible?
You can check the chartArea property that is available in the chart context. This property has the width and height of the area where the chart itself is being drawn.
const options = {
type: 'line',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
borderWidth: 1
},
{
label: '# of Points',
data: [7, 11, 5, 8, 3, 7],
borderWidth: 1
}
]
},
options: {}
}
const ctx = document.getElementById('chartJSContainer').getContext('2d');
const chart = new Chart(ctx, options);
console.log('height: ', chart.chartArea.height);
console.log('width: ', chart.chartArea.width)
<body>
<canvas id="chartJSContainer" width="600" height="400"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.6.2/chart.js"></script>
</body>
Your own code with the background colored pink: https://codepen.io/leelenaleee/pen/OJxWoPe
Official example on using an image as background: https://www.chartjs.org/docs/master/configuration/canvas-background.html#image

chart.js pie chart - how to update dataset with smooth transition

I have a chart.js pie chart. When I update the dataset, I want the pie segments to adjust size smoothly to the new values (i.e. grow/shrink in size).
The pie chart does the rotate transition every time. I can turn off the rotate transition with .update('none') after setting the new data, but then the pie chart instantly changes with no transition.
Is there a way to do this?
My pie chart setup code is:
chartRegion_Emissions_ANZIC_BreakdownChart = new Chart(ctx, {
type: 'pie',
options: {
responsive: true,
maintainAspectRatio: false,
plugins: {
tooltip: {
mode: 'nearest',
callbacks: {
label: function (tooltipItem, data) {
return tooltipItem.label + ': ' + addCommas(tooltipItem.raw) + 'kt';
}
}
}
}
},
data: {
labels: [],
datasets: []
}
});
and the update code (after AJAX request) is ...
chartRegion_Emissions_ANZIC_BreakdownChart.data.labels = data.labels;
chartRegion_Emissions_ANZIC_BreakdownChart.data.datasets[0] = data.data[0];
chartRegion_Emissions_ANZIC_BreakdownChart.update();//'none');
I'm using chart.js version 3.3.2... thanks for any help
Cheers
You override the entire dataset, if you instead of doing that only change the data of that dataset it will shrink/expand the segments of the data.
Example:
const options = {
type: 'pie',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
},
{
label: '# of Points',
data: [7, 11, 5, 8, 3, 7],
backgroundColor: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
}
]
},
options: {}
}
const ctx = document.getElementById('chartJSContainer').getContext('2d');
const chart = new Chart(ctx, options);
document.getElementById('update').addEventListener('click', () => {
chart.data.datasets[0].data = [10, 5, 12, 6, 8, 2];
chart.update();
})
<body>
<canvas id="chartJSContainer" width="600" height="400"></canvas>
<button id="update">
update data
</button>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.4.1/chart.js"></script>
</body>

Chartjs - Shift line plot to the right?

In Chartjs, is there any way to shift the line plot to the right 1 tick? Right now the line starts from the y-axis and as the result at the origin, there are labels from both x and y axis that does not look that nice. I attach the screenshot
Ideally I would like the 09-2016 to move to the right a litte. Really appreciate any help.
You can add an empty label and to the start of the labels array and a null value to the start of your dataArray to shift it a bit
Example:
var options = {
type: 'line',
data: {
labels: ["", "Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [null, 12, 19, 3, 5, 2, 3],
borderWidth: 1,
fill: false,
borderColor: 'red',
backgroundColor: 'red'
}]
},
options: {
scales: {
yAxes: [{
ticks: {
reverse: 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/2.9.4/Chart.js" integrity="sha512-hZf9Qhp3rlDJBvAKvmiG+goaaKRZA6LKUO35oK6EsM0/kjPK32Yw7URqrq3Q+Nvbbt8Usss+IekL7CRn83dYmw==" crossorigin="anonymous"></script>
</body>

who know how to put down the title of pie in ionic 2

I want to put the label under the pie.who know please tell me.thank you! here the code.
this.pieChart = new Chart(this.pieCanvas.nativeElement, {
type: 'pie',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: [
"#ff0000",
"#0000ff",
"#ffff00",
"#008000",
"#800080",
"#ffa500"
]
}]
}
});
You can achieve this by setting the label / legend 's position.
options: {
legend: {
position: 'bottom'
}
}
The full code would be like this ...
this.pieChart = new Chart(this.pieCanvas.nativeElement, {
type: 'pie',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: [
"#ff0000",
"#0000ff",
"#ffff00",
"#008000",
"#800080",
"#ffa500"
]
}]
},
options: {
legend: {
position: 'bottom'
}
}
});