Radar

Functional explanation

The Radar object plots several values around a circular web. Each axis, drawn as a spoke, represents one measurement, and each series is drawn as one closed polygon over all the axes. It suits comparisons over a fixed set of measurements, for example a setpoint against the actual value, two pumps over the same set of readings, or a machine profile against its reference profile.

The Radar object uses the same data structure as the Bar Graph object: the categories become the axes and the series become the polygons. A radar shows the shape of a profile rather than exact magnitudes, so keep the number of series small. Three or four polygons on one web are already hard to read.

Axis scaling is per axis by default. Every spoke is scaled from its own values, which keeps spokes with different units and different value ranges comparable in shape. Enable Shared Scale to place every spoke on one common range instead, which is what is needed when all spokes share the same unit and their magnitudes must be compared directly.

A value outside the range of its axis is drawn on the outer ring rather than outside the object, so a bad reading cannot push the graphic over the surrounding page content.

Object name

Set the object name shown in the radar decorator context.

Settings

Configure the chart behavior, the axis scaling, and the appearance of the web and the series polygons.

Axis Minimum and Axis Maximum apply to every axis. Leave them empty for automatic scaling. A Min or Max entered on a single axis in the Data section takes precedence over these two settings, and these two settings take precedence over the automatic range.

Data

The Data section defines the axes and the series. Add one Axes row per spoke and one Series row per polygon, then add one value per axis inside each series. Axis names, series names and values are all expressions, so a value can be a fixed number or a variable that is read at runtime.

Min and Max on an axis row are optional. Fill them in when that spoke needs its own range, for example when one spoke is a flow in m3/h and another is a temperature in degrees Celsius. Leave them empty to fall back to Axis Minimum and Axis Maximum, or to automatic scaling when those are empty as well.

The Expression field above the Axes list is an alternative to the two lists. Point it at a variable or expression that returns the complete data set as JSON and it takes precedence over the Axes and Series rows. Use it when the number of axes or series is decided at runtime rather than at design time.

{
  "categories": [
    { "name": "Flow", "min": 0, "max": 250 },
    { "name": "Head", "min": 0, "max": 60 },
    { "name": "Power", "min": 0, "max": 75 }
  ],
  "series": [
    { "name": "Pump 1", "color": "#87ceeb", "values": [180, 42, 55] },
    { "name": "Pump 2", "color": "#e9969b", "values": [165, 47, 61] }
  ]
}

A radar always draws at least three axes. If fewer axis names are entered than there are values in a series, the missing names are generated. If a series holds fewer values than there are axes, the missing values are drawn as 0.

Colors

Configure the color scheme for the radar elements. The polygon colors are set per series in the Data section.

Text

Configure the font settings for the legend, the axis labels around the web, and the ring value labels.

Position / Size

Configure the position and size of the Radar object. The web is sized from the smaller of the width and the height, so a square object uses the available area best.

Access Control

Configure access control for the Radar object.

Visibility

Configure the runtime visibility and blinking behavior for the Radar object.