Radar Chart API

Stack a few candidates over one shared set of criteria and read who wins where at a glance. See the Radar Chart demo.

Import

Web Component

import "@michi-vz/wc/radar-chart";
// <michi-vz-radar-chart> is now defined

Vanilla JS

import { mountRadarChart } from "@michi-vz/core";

const chart = mountRadarChart(el, props);

Props

Prop	Type	Default	Description
series*	RadarDataItem[]	—	Array of polygon series to plot, one closed shape per item drawn over the shared polar grid
axes*	string[]	—	spoke labels (the radial axes).
title	string	—	Optional chart title rendered above the plot
maxValue	number	—	Value mapped to the outer ring (full radius), shared by every spoke; defaults to the largest value across all series and axes (or 1 when all are zero)
rings	number	4	number of concentric grid rings (default 4).
fillOpacity	number	0.2	polygon fill opacity (default 0.2).
tooltipFormatter	(item: RadarDataItem) => string	—	Returns custom tooltip HTML for a hovered datum (sanitized before it is inserted)
onHighlightItem	(labels: string[]) => void	—	Called when the hovered/highlighted label(s) change

Common props — shared by every chart (14)

Prop	Type	Default	Description
width	number	600	Chart width in pixels
height	number	600	Chart height in pixels
margin	Margin	{ top: 60, right: 80, bottom: 60, left: 80 }	Inner margins (top/right/bottom/left, in px) reserved for axes, titles, and labels
colors	string[]	—	Categorical palette for series/labels without an explicit colour or colorsMapping entry
colorsMapping	Record<string, string>	—	Explicit label -> colour map; takes precedence over the palette and per-item colours
highlightItems	string[]	—	Labels to emphasise; all other marks dim
disabledItems	string[]	—	Labels to hide and exclude from scales/stacks
renderer	"svg" | "canvas"	"svg"	Render as inline SVG (default) or to a canvas (faster for large datasets); getContext() is identical either way
locale	string	—	BCP-47 locale used for number and date formatting
skipColorMappingDispatch	boolean	false	External-CSS mode: unmapped labels resolve to transparent and onColorMappingGenerated is not emitted, so mark colours come from your CSS via the data-label-safe contract
enableTransitions	boolean	true	Animate updates with CSS transitions (default true)
onColorMappingGenerated	(mapping: Record<string, string>) => void	—	Called with the resolved label -> colour map after the chart assigns colours
onChartDataProcessed	(context: ChartContext) => void	—	Called with the renderer-agnostic ChartContext whenever the data is (re)processed
onDataWarning	(warnings: DataWarning[]) => void	—	Called with any non-fatal data warnings (duplicate labels, non-finite values, gaps, ...)

Events

The web component dispatches these bubbling CustomEvents (the engine exposes the same via the on* callbacks in the table above):

Event	Detail	Fires when
michi-vz:highlight	string[]	hover highlight changes
michi-vz:colormapping	Record<string, string>	a color mapping is generated
michi-vz:dataprocessed	ChartContext	data is (re)processed
michi-vz:datawarning	DataWarning[]	input warnings are detected

getContext()

mountRadarChart(el, props).getContext() returns a renderer-agnostic RadarChartContext (structured stats + a deterministic natural-language summary + an a11y table). See LLM context.

Source

Props are typed as RadarChartProps in @michi-vz/core.