Bollinger Bands
Overview
Bollinger Bands are a technical analysis tool invented by John Bollinger in the 1980s. Having evolved from the concept of trading bands, Bollinger Bands can be used to measure the "highness" or "lowness" of the price relative to previous trades.
AnyChart Stock allows you to add Bollinger Bands with desired period to any of your charts.
Mathematical description of the indicator: Bollinger Bands.
Adding indicator
Bollinger Bands indicator is added using bbands() method. It requires a mapping with the value field in it:
var dataTable = anychart.data.table();
dataTable.addData(get_csco_daily_data());
// map loaded data
var mapping = dataTable.mapAs({'value': 4});
// create stock chart
chart = anychart.stock();
// create plot on the chart
var plot = chart.plot(0);
// create Bollinger Bands indicator
var bbands = plot.bbands(mapping);
Indicator parameters
Bollinger Bands indicator only required parameter is the "mapping". Optional parameters are: "period", "deviation", "middle", "upper" and "lower" series types.
var bbands = plot.bbands(mapping, 10, 3, "spline", "spline", "spline");
Visualization using lines
Visualization of an indicator depends on the type of a series you display it with. Here is a sample where all series of the Bollinger Bands indicator are colored:
var bbands = plot.bbands(mapping);
// color the series
bbands.upperSeries().stroke('#bf360c');
bbands.middleSeries().stroke('#ff6600');
bbands.lowerSeries().stroke('#bf360c');
Live sample:
Visualization using ranges
Visualization of the Bollinger Bands indicator can be done with Range series - Range Area, Range Spline Area, etc.
The sample below uses Range Spline Area for the Bollinger Bands indicator visualization.