Radar

Who it’s for

Anyone judging a profile rather than a number — a machine scored across vibration, temperature, load and noise; a site rated on several environmental measures; a device compared against the shape a healthy one produces. The reader is matching an outline against an expectation, and the outline is the finding.

What it does

The Radar chart places each data key on its own axis around a circle and joins the latest values into a closed shape. Three keys reading Wind = 40, Solar = 35 and Hydroelectric = 25 produce a triangle whose lopsidedness is the point — a balanced profile draws a regular shape, and one weak axis pulls the outline visibly in.

• The shape is the message — a reader recognizes a familiar outline far faster than they read four separate values.
• Axes can share one scale or each carry their own, which is the difference between “how do these compare” and “how does each stand against its own range”.
• Line, points and fill are configurable independently, so an outline can be drawn as a bare shape or as a filled region.
• Point labels put values on the shape itself, removing the need to cross-reference the legend.
• The chart shape can be switched between polygon and circle to suit the number of axes.
• Axis and tick labels take their own fonts, which matters when axis names are long.
• The Radar chart plots the latest value of each key: it shows no history, and it needs at least three axes to draw a shape at all.

How to set up

Data keys

The Radar chart takes one axis per data key, from one or more datasources.

Key	Role	Type	Description
Wind	One axis, with the shape’s vertex at its latest value	Timeseries	Numeric values only. Attributes work equally well. Add one key per axis, three at minimum; the key’s label names the axis. Keys are placed around the circle in order.

Decide the axis scaling before anything else. With Max axes scaling set to Common, every axis shares the highest value across the dataset, so axes are directly comparable; set to Separate, each axis scales to its own maximum, so every measure uses its full range and the shape shows relative standing rather than absolute size.

How to customize

• To compare axes against each other or against themselves — set Max axes scaling to Common or Separate.
• To change the outline’s geometry — set Shape to a polygon or a circle.
• To draw a filled region instead of an outline — configure the fill settings, and set Line type and width for the edge.
• To mark each reading on the shape — turn on Points and set their shape and size.
• To print values on the shape — turn on Points label, set its position, font and color.
• To handle long axis names — set the Axis label font, or turn axis labels off and rely on the legend.
• To show the tick scale — turn on Ticks label and set its font and color.
• To keep the axis order stable — turn on Sort series by label.

Tips

• Choose Common scaling only when the axes genuinely share a unit. Across mixed measures it makes the largest-numbered axis dominate the shape, and the profile then describes the units rather than the machine.
• Keep to between three and about eight axes. Below three there is no shape, and past eight the outline turns into a circle in which no single weak axis is visible — which is the one thing the chart exists to show.