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Smoothing in charts

Neptune may transform the data displayed on charts by applying the following:

  • Rendering algorithm when fetching data from the servers, if the original values are too many to be displayed.
  • Smoothing function controlled by the slider next to the chart.
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Neptune can always retrieve 100% accurate values. You can increase the precision of displayed values by zooming in.

Smoothing function​

The smoothing function is manually controlled with the slider in the chart settings.

A chart with and without the manual smoothing applied.

When you move the smoothing slider, Neptune applies a simple moving average (SMA) calculation on the y values that are displayed on the chart.

Current limitations
  • In case data points aren't distributed uniformly over the X axis, the average value, as calculated by the SMA smoothing algorithm, may differ from actual average value of the continuous function over the given range.
  • When a chart is zoomed in, only points in the visible range are retrieved and taken into account when smoothing is performed. This can lead to reduced smoothing precision at the edges of the visible range.

Rendering algorithm ("downsampling")​

Neptune renders charts based on all data points. If there are too many original points to display at once, Neptune renders aggregated values.

To ensure uniform distribution of all data points, the rendering algorithm divides the X axis of a chart into ranges of the same length, then selects a data point to display for each range.

  • If a series has multiple values logged in a given range, the average of the y values is displayed. In addition, the shaded area on the chart represents the minimum and maximum values for that range.

  • If a series doesn't have values logged in a given range, the displayed data point is interpolated based on the values of the surrounding points.