How do we create an OHLC chart with moving average using google chart API - google-api

Question

I am using google API to create charts. I am able to create OHLC(Candlestick) charts. But I want to add an overlay of Moving Average to it. Can anyone please guide me as to how I can do it?
Thanks in advance.

Answer 1

Here's an example of how to add a moving average line to a CandlestickChart:
function drawChart() {
var data = new google.visualization.DataTable();
data.addColumn('date', 'Date');
data.addColumn('number', 'Low');
data.addColumn('number', 'Open');
data.addColumn('number', 'Close');
data.addColumn('number', 'High');
var low, open, close = 45, high;
for (var i = 0; i < 30; i++) {
open = close;
close += ~~(Math.random() * 10) * Math.pow(-1, ~~(Math.random() * 2));
high = Math.max(open, close) + ~~(Math.random() * 10);
low = Math.min(open, close) - ~~(Math.random() * 10);
data.addRow([new Date(2014, 0, i + 1), low, open, close, high]);
}
// use a DataView to calculate an x-day moving average
var days = 5;
var view = new google.visualization.DataView(data);
view.setColumns([0, 1, 2, 3, 4, {
type: 'number',
label: days + '-day Moving Average',
calc: function (dt, row) {
// calculate average of closing value for last x days,
// if we are x or more days into the data set
if (row >= days - 1) {
var total = 0;
for (var i = 0; i < days; i++) {
total += dt.getValue(row - i, 3);
}
var avg = total / days;
return {v: avg, f: avg.toFixed(2)};
}
else {
// return null for < x days
return null;
}
}
}]);
var chart = new google.visualization.ComboChart(document.querySelector('#chart_div'));
chart.draw(view, {
height: 400,
width: 600,
chartArea: {
left: '7%',
width: '70%'
},
series: {
0: {
type: 'candlesticks'
},
1: {
type: 'line'
}
}
});
}
google.load("visualization", "1", {packages:["corechart"], callback: drawChart});
see it working here: http://jsfiddle.net/asgallant/74u6ox8b/