function getAverages(rowVals) {
let averages = ''
rowVals.forEach(function(arr, i) {
if (i != 0)
averages += '<td>' + (arr.reduce(function(a, b) {
return a + b;
}) / arr.length).toFixed(1) + '</td>'
});
return averages
}
function addHtmlTableAverage() {
var table = $('.highcharts-data-table table')[0],
avgVal, sumVal = 0,
rowCount = table.rows.length - 1,
rowVals = [
[]
]; // minus the header
for (var i = 1; i < table.rows.length; i++) {
for (let j = 1; j < table.rows[i].cells.length; j++) {
if (rowVals[j]) {
rowVals[j].push(parseFloat(table.rows[i].cells[j].innerHTML))
} else {
rowVals.push([parseFloat(table.rows[i].cells[j].innerHTML)])
}
}
}
$('.highcharts-data-table table > tbody:last')
.append('<tr class="averages"><td><b>Avg</b></td>' +
getAverages(rowVals) +
"</tr>")
}
/**
* Create the chart
*/
window.chart = Highcharts.chart('container', {
chart: {
events: {
load: function() {
this.viewData()
addHtmlTableAverage()
}
},
borderWidth: 2,
width: 600,
height: 300
},
title: {
text: 'Average monthly temperatures'
},
xAxis: {
categories: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
},
yAxis: {
title: {
text: 'Temperature (°C)'
}
},
series: [{
name: 'Tokyo',
data: [7.0, 6.9, 9.5, 14.5, 18.2, 21.5, 25.2, 26.5, 23.3, 18.3, 13.9, 9.6]
}, {
name: 'New York',
data: [-0.2, 0.8, 5.7, 11.3, 17.0, 22.0, 24.8, 24.1, 20.1, 14.1, 8.6, 2.5]
}, {
name: 'Berlin',
data: [-0.9, 0.6, 3.5, 8.4, 13.5, 17.0, 18.6, 17.9, 14.3, 9.0, 3.9, 1.0]
}, {
name: 'London',
data: [3.9, 4.2, 5.7, 8.5, 11.9, 15.2, 17.0, 16.6, 14.2, 10.3, 6.6, 4.8]
}]
});
#container {
margin-top: 20px;
}
.highcharts-data-table thead {
background-color: #aaa;
}
.averages td {
background-color: #ccc;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://code.highcharts.com/highcharts.js"></script>
<script src="https://code.highcharts.com/modules/exporting.js"></script>
<script src="https://code.highcharts.com/modules/export-data.js"></script>
<div id="container"></div>