I am trying to fill the area between two lines in a line chart using Chart.js. Like this:
There is already an answer here, that explains how to extend chartjs to do
Make sure you import the 2.6.0 version:
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.min.js"></script>
Then follow the rules as described here: http://www.chartjs.org/docs/latest/charts/area.html
Below is an example, and how it looks:
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>My two lines with colour between them</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.min.js"></script>
</head>
<body>
<canvas id="mychart" width="300" height="200"></canvas>
<script>
var ctx = document.getElementById('mychart').getContext('2d'); //get the context (canvas)
var config = { //configure the chart
type: 'line',
data: {
labels: [1, 2, 3, 4],
datasets: [{
label: "Min",
backgroundColor: 'rgba(55, 173, 221, 0.6)',
borderColor: 'rgba(55, 173, 221, 1.0)',
fill: false, //no fill here
data: [5, 5, 3, 2]
},
{
label: "Max",
backgroundColor: 'rgba(55, 173, 221, 0.6)',
borderColor: 'rgba(55, 173, 221, 1.0)',
fill: '-1', //fill until previous dataset
data: [8, 7, 6, 5]
}]
},
options: {
maintainAspectRatio: false,
spanGaps: false,
elements: {
line: {
tension: 0.000001
}
},
plugins: {
filler: {
propagate: false
}
},
scales: {
xAxes: [{
ticks: {
autoSkip: false
}
}]
}
}
};
var chart = new Chart(ctx, config);
</script>
</body>
</html>
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)'
}]
See this: https://www.chartjs.org/samples/latest/charts/area/line-datasets.html
Here is a small plugin that can do shading between any two dataset lines.
https://stackoverflow.com/a/41733045/852977