Chart JS Fill Between two lines - chart.js

I am looking for a way to fill between two lines with Chart.js so that it would look like this. I have looked and everything seems to talk about filling between two lines across zero. I also need other lines to fill all the way down like normal. Is this something chart.js can do?

Here is a solution that uses a plugin to fill between two datasets. Supports all line styles and fill shading between multiple lines. To fill between a dataset, use the custom param fillBetweenSet to tell a dataset to fill the area between another dataset.
Fiddle - https://jsfiddle.net/ke5n5LnL/26/
Preview:
Code:
<html>
<div>
<canvas id="demo"></canvas>
</div>
</html>
<script>
var fillBetweenLinesPlugin = {
afterDatasetsDraw: function (chart) {
var ctx = chart.chart.ctx;
var xaxis = chart.scales['x-axis-0'];
var yaxis = chart.scales['y-axis-0'];
var datasets = chart.data.datasets;
ctx.save();
for (var d = 0; d < datasets.length; d++) {
var dataset = datasets[d];
if (dataset.fillBetweenSet == undefined) {
continue;
}
// get meta for both data sets
var meta1 = chart.getDatasetMeta(d);
var meta2 = chart.getDatasetMeta(dataset.fillBetweenSet);
// do not draw fill if one of the datasets is hidden
if (meta1.hidden || meta2.hidden) continue;
// create fill areas in pairs
for (var p = 0; p < meta1.data.length-1;p++) {
// if null skip
if (dataset.data[p] == null || dataset.data[p+1] == null) continue;
ctx.beginPath();
// trace line 1
var curr = meta1.data[p];
var next = meta1.data[p+1];
ctx.moveTo(curr._view.x, curr._view.y);
ctx.lineTo(curr._view.x, curr._view.y);
if (curr._view.steppedLine === true) {
ctx.lineTo(next._view.x, curr._view.y);
ctx.lineTo(next._view.x, next._view.y);
}
else if (next._view.tension === 0) {
ctx.lineTo(next._view.x, next._view.y);
}
else {
ctx.bezierCurveTo(
curr._view.controlPointNextX,
curr._view.controlPointNextY,
next._view.controlPointPreviousX,
next._view.controlPointPreviousY,
next._view.x,
next._view.y
);
}
// connect dataset1 to dataset2
var curr = meta2.data[p+1];
var next = meta2.data[p];
ctx.lineTo(curr._view.x, curr._view.y);
// trace BACKWORDS set2 to complete the box
if (curr._view.steppedLine === true) {
ctx.lineTo(curr._view.x, next._view.y);
ctx.lineTo(next._view.x, next._view.y);
}
else if (next._view.tension === 0) {
ctx.lineTo(next._view.x, next._view.y);
}
else {
// reverse bezier
ctx.bezierCurveTo(
curr._view.controlPointPreviousX,
curr._view.controlPointPreviousY,
next._view.controlPointNextX,
next._view.controlPointNextY,
next._view.x,
next._view.y
);
}
// close the loop and fill with shading
ctx.closePath();
ctx.fillStyle = dataset.fillBetweenColor || "rgba(0,0,0,0.1)";
ctx.fill();
} // end for p loop
}
} // end afterDatasetsDraw
}; // end fillBetweenLinesPlugin
Chart.pluginService.register(fillBetweenLinesPlugin);
var chartData = {
labels: [1, 2, 3, 4, 5,6,7,8],
datasets: [
{
label: "Set 1",
data: [10, 20, null, 40, 30,null,20,40],
borderColor: "#F00",
fill: false,
steppedLine: false,
tension: 0,
fillBetweenSet: 1,
fillBetweenColor: "rgba(255,0,0, 0.2)"
},
{
label: "Set 2",
data: [60, 40, 10, 50, 60,null,50,20],
borderColor: "#00F",
fill: false,
steppedLine: false,
tension: 0.5
},
{
label: "Set 2",
data: [40, 50, 30, 30, 20,null,60,40],
borderColor: "#0D0",
fill: false,
steppedLine: false,
tension: 0,
fillBetweenSet: 1,
fillBetweenColor: "rgba(5,5,255, 0.2)"
}
]
};
var chartOptions = {
responsive: true,
title: {
display: true,
text: 'Demo Fill between lines'
}
};
var chartDemo = new Chart($('#demo').get(0), {
type: 'line',
data: chartData,
options: chartOptions
});
</script>

Setting fill property to +1 of a dataset will set the backgroundColor from this line to the next line in dataset.
datasets: [{
label: 'Systolic Guideline',
data: [],
fill: '+1',
borderColor: '#FFC108',
backgroundColor: 'rgba(255,193,8,0.2)'
},
{
label: 'Diastolic Guideline',
data: [],
fill: true,
borderColor: '#FFC108',
backgroundColor: 'rgba(0,0,0,0)'
}]

On chart.js v2.0 you have this feature now inside. See https://www.chartjs.org/samples/latest/charts/area/line-datasets.html

Related

Line chart out of axis boundary after extended the chart draw function

I referred to "How to change line segment color of a line graph in Chart.js" and extended the chart to redraw the line segment with a different color.
But after adding plugin "chartjs-plugin-zoom" to support zoom in/out the chart, I could see the line chart is out of axis boundary. See the following code.
https://jsfiddle.net/sd9rx84g/2/
var ctx = document.getElementById('myChart').getContext('2d');
//adding custom chart type
Chart.defaults.multicolorLine = Chart.defaults.line;
Chart.controllers.multicolorLine = Chart.controllers.line.extend({
draw: function(ease) {
var
startIndex = 0,
meta = this.getMeta(),
points = meta.data || [],
colors = this.getDataset().colors,
area = this.chart.chartArea,
originalDatasets = meta.dataset._children
.filter(function(data) {
return !isNaN(data._view.y);
});
function _setColor(newColor, meta) {
meta.dataset._view.borderColor = newColor;
}
if (!colors) {
Chart.controllers.line.prototype.draw.call(this, ease);
return;
}
for (var i = 2; i <= colors.length; i++) {
if (colors[i-1] !== colors[i]) {
_setColor(colors[i-1], meta);
meta.dataset._children = originalDatasets.slice(startIndex, i);
meta.dataset.draw();
startIndex = i - 1;
}
}
meta.dataset._children = originalDatasets.slice(startIndex);
meta.dataset.draw();
meta.dataset._children = originalDatasets;
points.forEach(function(point) {
point.draw(area);
});
}
});
var chart = new Chart(ctx, {
// The type of chart we want to create
type: 'multicolorLine',
// The data for our dataset
data: {
labels: ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12"],
datasets: [{
label: "My First dataset",
borderColor: 'rgb(255, 99, 132)',
data: [35, 10, 5, 2, 20, 30, 45, 0, 10, 5, 2, 20, 30, 45],
//first color is not important
colors: ['', 'red', 'green', 'blue', 'red', 'brown', 'black']
}]
},
// Configuration options go here
options: {
plugins: {
zoom: {
pan: {
// pan options and/or events
enabled: true,
mode: 'xy'
},
zoom: {
enabled: true,
drag: false,
mode: 'x',
speed: 1
}
}
}
}
});
<script src="https://cdn.jsdelivr.net/npm/chart.js#2.9.3"></script>
<script src="https://cdn.jsdelivr.net/npm/hammerjs#2.0.8"></script>
<script src="https://cdn.jsdelivr.net/npm/chartjs-plugin-zoom#0.7.7"></script>
<canvas id="myChart"></canvas>
line chart out of axis boundary
How can I resolve this issue?
Thanks
Forrest

ChartJS line-chart set background-opacity

I've tried multiple examples but i'm unable to get my line-chart to have background-transparency, as of now, it's blue, but the color i'm trying to set is orange (rgba(255, 145, 68, 0.2)).
TL;DR: How do I set the fill-opacity on my line-chart graph?
I've followed countless of tutorials, but all of them seem to set the background-color in dataset, which is not what I want, since i'm using dynamic data. The code is in a TypeScript component with tons of functionality built upon it, so it's quite hard to extract the code and make it work in a jsfiddle.
When i set fill:true under elements: { line: { the graph will get the fill as shown in the image below. But i'm unable to set the background-opacity here,
I've tried these attributes: backgroundColor, fillColor
Here's the code atleast:
import {
Component
} from '../../decorators/component.decorator';
import * as EsChart from '../../../../node_modules/chart.js/dist/Chart.bundle.js';
import * as angular from 'angular';
#Component({
templateUrl: 'app/dashboard-components/es-line-chart/es-line-chart.component.html',
bindings: {
esLineChartId: '#',
chartTitle: '#',
labels: '#',
esScaleMax: '#',
esScaleMaxSecond: '#',
esScaleStepW: '#',
esScaleStepWSecond: '#',
esScaleMin: '#',
esScaleMinSecond: '#',
lowerOkValue: '#',
targetValue: '#',
upperOkValue: '#',
chartDataValueSuffix: '#',
datasets: '#',
esXLabelSkips: '#'
}
})
export default class LineChartComponent {
$ctrl: any = this;
getChartOptions(lineChartData, secondYAxis, xLabelSkips) {
return {
type: 'line',
data: lineChartData,
options: {
responsive: true,
maintainAspectRatio: false,
title: {
display: true,
text: this.$ctrl.chartTitle
},
legend: {
display: true,
labels: {
boxWidth: 12
}
},
tooltips: {
enabled: true,
mode: 'index',
intersect: false,
filter: function(tooltipItem, data) {
return !data.datasets[tooltipItem.datasetIndex].tooltipHidden;
},
callbacks: {
label: function(tooltipItem, data) {
var currentDataset = data.datasets[tooltipItem.datasetIndex];
var label = currentDataset.label + ': ';
label += currentDataset.data[tooltipItem.index] + (currentDataset.dataSuffix ? " " + currentDataset.dataSuffix : "");
return label;
}
}
},
elements: {
line: {
tension: 0, // disables bezier curves
borderWidth: 3, // Line stroke width in pixels
fill: true,
fillColor: "rgba(255, 145, 68, 0.2)",
strokeColor: "rgba(255, 145, 68, 0.2)",
pointColor: "rgba(255, 145, 68, 1)",
pointStrokeColor: "#fff",
pointHighlightFill: "#fff",
pointHighlightStroke: "rgba(255, 145, 68, 1)"
},
point: { // disable the circles/points in the chart lines
radius: 0,
hitRadius: 0,
hoverRadius: 0
},
},
scales: {
xAxes: [{
display: true,
type: 'category',
ticks: {
autoSkip: xLabelSkips,
maxRotation: 45
},
afterFit: (scale) => {
scale.height = 100;
}
}],
yAxes: [{
id: 'y-axis-0',
display: true,
position: 'left',
ticks: {
stepSize: this.$ctrl.esScaleStepW ? eval(this.$ctrl.esScaleStepW) : 0.5, // grid lines on yAxis with value distance of stepSize
suggestedMin: (eval(this.$ctrl.esScaleMin)),
suggestedMax: (eval(this.$ctrl.esScaleMax))
}
},
{
id: 'y-axis-1',
display: secondYAxis,
position: 'right',
ticks: {
stepSize: this.$ctrl.esScaleStepWSecond ? eval(this.$ctrl.esScaleStepWSecond) : 0.5, // grid lines on yAxis with value distance of stepSize
suggestedMin: (eval(this.$ctrl.esScaleMinSecond)),
suggestedMax: (eval(this.$ctrl.esScaleMaxSecond))
}
}
]
}
}
};
}
getExtraDatasets(datasetType: string, dataLabel: string, fillValue: number, chartSpan: number) {
var dataFill = [];
for (var i = 0; i < chartSpan; i++) {
dataFill.push(fillValue);
}
return {
label: dataLabel,
borderColor: datasetType === "limit" ? 'rgba(205, 8, 4, 1)' : datasetType === "target" ? 'rgba(20, 180, 2, 1)' : 'rgba(0, 0, 0, 0.5)',
borderWidth: 0.5,
//tooltipHidden: true,
data: dataFill
};
}
removeEmptyDatasets() {
//var test = "[{label: 'Verklig cykeltid',borderColor: 'rgba(60, 141, 188, 0.75)',borderWidth: 4,data: },{label: 'Kalkylerad cykeltid',borderColor: 'rgba(205, 108, 104, 0.75)',borderWidth: 4,data: [59]}]";
this.$ctrl.datasets = this.$ctrl.datasets.replace(/data: *,/g, "data: [],");
this.$ctrl.datasets = this.$ctrl.datasets.replace(/data: *}/g, "data: []}");
this.$ctrl.datasets = this.$ctrl.datasets.replace(/: *,/g, ": 0,");
this.$ctrl.datasets = this.$ctrl.datasets.replace(/: *}/g, ": 0}");
var sets = this.$ctrl.datasets.match(/\{[^\{\}]*\}/g);
for (var i = 0; i < sets.length; i++) {
if (sets[i].match(/data: *\[\]/g)) {
//console.log("no data", sets[i]);
sets[i] = "";
}
}
this.$ctrl.datasets = ("[" + (sets.join()).replace(/^,|,$/g, "") + "]");
}
$onInit() {
var canvas = $("#" + this.$ctrl.esLineChartId + " .lineChart").get(0).getContext("2d");
this.removeEmptyDatasets();
//console.log(this.$ctrl.datasets);
var lineChartData = {
labels: this.$ctrl.labels ? eval(this.$ctrl.labels) : [],
datasets: this.$ctrl.datasets ? eval(this.$ctrl.datasets) : []
};
if (this.$ctrl.upperOkValue) {
lineChartData.datasets = lineChartData.datasets.concat(this.getExtraDatasets("limit", "Övre gräns", eval(this.$ctrl.upperOkValue), (lineChartData.labels).length));
}
if (this.$ctrl.targetValue) {
lineChartData.datasets = lineChartData.datasets.concat(this.getExtraDatasets("target", "Målvärde", eval(this.$ctrl.targetValue), (lineChartData.labels).length));
}
if (this.$ctrl.lowerOkValue) {
lineChartData.datasets = lineChartData.datasets.concat(this.getExtraDatasets("limit", "Undre gräns", eval(this.$ctrl.lowerOkValue), (lineChartData.labels).length));
}
var secondYAxis = false;
for (var i = 0; i < (lineChartData.datasets).length; i++) {
// set backgroundColor to be the same as borderColor so that tooltip and legend items look better
(lineChartData.datasets[i]).backgroundColor = (lineChartData.datasets[i]).borderColor;
// Activate the second y axis if a dataset uses it
if ((lineChartData.datasets[i]).yAxisID == 'y-axis-1') {
secondYAxis = true;
}
// Use standard data suffix if defined and no special data suffix is defined for the dataset
if (!((lineChartData.datasets[i]).dataSuffix) && (this.$ctrl.chartDataValueSuffix)) {
(lineChartData.datasets[i]).dataSuffix = this.$ctrl.chartDataValueSuffix;
}
}
var xLabelSkips = this.$ctrl.esXLabelSkips ? eval(this.$ctrl.esXLabelSkips) : false;
var chartOptions = this.getChartOptions(lineChartData, secondYAxis, xLabelSkips);
var lineChart = new EsChart(canvas, chartOptions);
}
}
resources i've followed:
http://tobiasahlin.com/blog/chartjs-charts-to-get-you-started/
https://www.chartjs.org/docs/latest/configuration/elements.html
https://canvasjs.com/docs/charts/chart-options/data/fill-opacity/
Image:

Show highest value untop of a bars when dataset is stacked (chartjs)

I have this code:
animation: {
duration: 500,
onComplete: function() {
var ctx = this.chart.ctx;
var chart = this;
ctx.textAlign = "center";
ctx.textBaseline = "middle";
var datasets = this.config.data.datasets;
ctx.font = "15px QuickSand";
datasets.forEach(function (dataset, i) {
switch ( chart.getDatasetMeta(i).type ) {
case "bar":
ctx.fillStyle = "#303030";
chart.getDatasetMeta(i).data.forEach(function (p, j)
{
ctx.fillText(datasets[i].data[j], p._model.x, p._model.y - 10);
});
break;
}
});
}
}
And these datasets:
datasets: [
{
backgroundColor: '#f87979',
data: [6500, 5500]},
{
backgroundColor: '#f8f8ee',
data: [4800, 5600]
}
]
The dataset is set to be stacked using.
scales: {
xAxes: [{
barThickness: 25,
stacked: true,
ticks: {
beginAtZero: true,
padding: 0,
fontSize: 13
}
}],
yAxes: [{
stacked: true,
display: false
}]
},
What the above code does is placing the values over the bars. My problem is that i want to show the highest value from each dataset at above each bar.
And not all the values from each point.
Can you guys help me with this? I have been trying to do this for like a 1 day now.
To clearify instead of this:
Image with all values
I want this:
Image with wanted values
check out this jsfiddle: https://jsfiddle.net/umsbywLg/2/
essentially I calculated the max value and then drew that on top on the stacked bars:
onComplete: function() {
var ctx = this.chart.ctx;
var chart = this;
ctx.textAlign = "center";
ctx.textBaseline = "middle";
var datasets = this.config.data.datasets;
ctx.font = "15px QuickSand";
ctx.fillStyle = "#303030";
datasets.forEach(function (dataset, i) {
var maxValue = 0;
chart.getDatasetMeta(i).data.forEach(function (p, j) {
if(maxValue < datasets[j].data[i]) {
maxValue = datasets[j].data[i];
}
});
ctx.fillText(maxValue, datasets[i]._meta[0].data[i]._view.x, 20);
});
}

Chart.js legend customisation

I have a bit of a strange config of my chart.js because of the data that is being fed into it and also the line colours. However I was wondering if somebody could point me in the direction of how to customise the legend:
$(document).ready(function(){
$.ajax({
url : "../acredash/teamData.php",
timeout: 4000,
type : "GET",
success :function(data){
console.log(data);
var chartata = {
labels: [
"Strategic Development and Ownership",
"Driving change through others",
"Exec Disposition",
"Commercial Acumen",
"Develops High Performance Teams",
"Innovation and risk taking",
"Global Leadership",
"Industry Leader"
]};
var ctx = $("#mycanvas");
var config = {
type: 'radar',
data: chartata,
animationEasing: 'linear',
options: {
legend: {
display: true,
position: 'bottom'
},
tooltips: {
enabled: true
},
scale: {
ticks: {
fontSize: 15,
beginAtZero: true,
stepSize: 1
}
}
},
},
LineGraph = new Chart(ctx, config);
var colorArray = [
["#7149a5", false],
["#57B6DD", false],
["#36bfbf", false],
["#69bd45", false],
['#9adfdf', false],
['#c6b6db' ,false],
["#5481B1", false],
['#8d6db7', false],
['#d2ebc7', false],
["#6168AC", false]
];
for (var i in data) {
tmpscore=[];
tmpscore.push(data[i].score_1);
tmpscore.push(data[i].score_2);
tmpscore.push(data[i].score_3);
tmpscore.push(data[i].score_4);
tmpscore.push(data[i].score_5);
tmpscore.push(data[i].score_6);
tmpscore.push(data[i].score_7);
tmpscore.push(data[i].score_8);
var color, done = false;
while (!done) {
var test = colorArray[parseInt(Math.random() * 10)];
if (!test[1]) {
color = test[0];
colorArray[colorArray.indexOf(test)][1] = true;
done = !done;
}
}
newDataset = {
label: data[i].firstName+' '+data[i].lastName,
borderColor: color,
backgroundColor: "rgba(0,0,0,0)",
data: tmpscore,
};
config.data.datasets.push(newDataset);
}
LineGraph.update();
},
});
});
I have looked around without much luck because of how my chart is being generated. It just used the default legend and its a it messy. I would like to just have control over it.
Step 1:
set callback for legend on options
legendCallback: function(chart) {
var legendHtml = [];
legendHtml.push('<ul>');
var item = chart.data.datasets[0];
for (var i=0; i < item.data.length; i++) {
legendHtml.push('<li>');
legendHtml.push('<span></span>');//add what ever you want :-p
legendHtml.push('<span class="chart-legend-label-text">' + chart.data.labels[i]+'</span>');
legendHtml.push('</li>');
}
legendHtml.push('</ul>');
return legendHtml.join("");
},legend:false,
Step 2:
Place your legend where ever you want :-p
<div id="my-legend-con" class="legend-con"></div>
Step 3:
Initialise the legend.
$('#my-legend-con').html(myChartName.generateLegend());
Step 3:
Do what ever you want...

In ChartJS is it possible to change the line style between different points?

Using ChartJs (v2.2.2) can you change the line style between the last 2 points on a graph. e.g. have a solid line all the way and then dashed at the end? see picture below
The borderDashproperty (scroll to Line Configuration) is the key to your problem.
The thing is, the full chart is drawn with a border dash, you cannot choose where it starts and where it ends.
A simple workaround is to create two identical datasets. One dotted and one with a plain line. Then you remvoe the last data of your plain one, and they both will be displayed as how you want it.
You can see the full code in this jsFiddle, and here is its result :
Note :
Since there are two datasets now, the legend will display both of them. Setting the display to false fixes it (more or less).
The declaration order doesn't matter since the plain line will always overwrite the dotted one.
Having a bezier curve (tension property > 0) can create a display problem since the data is not the same in both datasets.
You can create a scatter chart and draw the lines directly on the canvas using the Plugin Core API. The API offers a range of hooks that can be used for performing custom code. The advantage of this approach is that you can customize the style of every single connection line (width, color, dash pattern etc.).
const labels = [1, 2, 3, 4, 5, 6];
const values = [12, 19, 3, 5, 2, 3];
const data = labels.map((label, index) => ({ x: label, y: values[index]}));
var lineChart = new Chart(document.getElementById("chart"), {
type: "scatter",
plugins: [{
afterDraw: chart => {
var ctx = chart.chart.ctx;
var xAxis = chart.scales['x-axis-1'];
var yAxis = chart.scales['y-axis-1'];
chart.config.data.datasets[0].data.forEach((value, index) => {
if (index > 0) {
var valueFrom = data[index - 1];
var xFrom = xAxis.getPixelForValue(valueFrom.x);
var yFrom = yAxis.getPixelForValue(valueFrom.y);
var xTo = xAxis.getPixelForValue(value.x);
var yTo = yAxis.getPixelForValue(value.y);
ctx.save();
ctx.strokeStyle = '#922893';
ctx.lineWidth = 2;
if (index + 1 == data.length) {
ctx.setLineDash([5, 10]);
}
ctx.beginPath();
ctx.moveTo(xFrom, yFrom);
ctx.lineTo(xTo, yTo);
ctx.stroke();
ctx.restore();
}
});
}
}],
data: {
datasets: [{
label: "My Dataset",
data: data,
borderColor: '#922893',
pointBackgroundColor: "transparent"
}]
},
options: {
legend: {
display: false
},
scales: {
xAxes: [{
ticks: {
stepSize: 1
}
}],
yAxes: [{
ticks: {
beginAtZero: true
}
}]
}
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.9.3/Chart.min.js"></script>
<canvas id="chart" height="90"></canvas>
const labels = [1, 2, 3, 4, 5, 6];
const values = [12, 19, 3, 5, 2, 3];
const data = labels.map((label, index) => ({ x: label, y: values[index]}));
var lineChart = new Chart(document.getElementById("chart"), {
type: "scatter",
plugins: [{
afterDraw: chart => {
var ctx = chart.chart.ctx;
var xAxis = chart.scales['x-axis-1'];
var yAxis = chart.scales['y-axis-1'];
chart.config.data.datasets[0].data.forEach((value, index) => {
if (index > 0) {
var valueFrom = data[index - 1];
var xFrom = xAxis.getPixelForValue(valueFrom.x);
var yFrom = yAxis.getPixelForValue(valueFrom.y);
var xTo = xAxis.getPixelForValue(value.x);
var yTo = yAxis.getPixelForValue(value.y);
ctx.save();
ctx.strokeStyle = '#922893';
ctx.lineWidth = 2;
if (index + 1 == data.length) {
ctx.setLineDash([5, 10]);
}
ctx.beginPath();
ctx.moveTo(xFrom, yFrom);
ctx.lineTo(xTo, yTo);
ctx.stroke();
ctx.restore();
}
});
}
}],
data: {
datasets: [{
label: "My Dataset",
data: data,
borderColor: '#922893',
pointBackgroundColor: "transparent"
}]
},
options: {
legend: {
display: false
},
scales: {
xAxes: [{
ticks: {
stepSize: 1
}
}],
yAxes: [{
ticks: {
beginAtZero: true
}
}]
}
}
});
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