Bell curve

A bell curve series is a graphical representation of a normal (Gaussian) probability distribution. Bell curve is used to visualize the probability of occurring outcomes. The curve is bell-shaped, and its center top point is the mean of the base data.

For more detailed samples and documentation check the API. 

Click here  to check the code.

How to create a Bell Curve

The bell curve requires the following module modules/histogram-bellcurve.js .

The bell curve series is an areaspline series with self-setting data. Unlike most other Highcharts series, the data  property is not available - it is set internally based on the base series data (more precisely y values of the data).

Two steps are required to create a bell curve:

1. Set the series type to bellcurve.

2. Set baseSeries to the right data series’ id or index.

series: [{
    type: 'bellcurve',
    xAxis: 1,
    yAxis: 1,
    baseSeries: 1
}, {
    data: [3.5, 3, 3.2, 3.1, 3.6, 3.9, 3.4]
}]

Setting the Bell Curve

A bell curve series has two additional options:

• intervals: to control the length of the curve.
• pointsInInterval: to control the number of points within one interval, i.e., the number of points between σn and σn+1.

The following demo visualizes four intervals for each side of the bell curve, and five points between each Nxσ:

series: [{
    type: 'bellcurve',
    intervals: 4,
    pointsInInterval: 5
    ...
}]

Click here  to check the code.

The black markers indicate the borders of the intervals - four intervals for each side of the curve. Within one interval there are four markers plus the border black marker. On the left side intervals are left-closed, on the right side right-closed. The interval length is the bell curve’s standard deviation.

Additionally, there is one point at the top which is the mean of the bell curve.