How do I create a polar / radar chart in JavaScript?

Install with `npm install katucharts.js`, then call KatuCharts.chart(container, { chart: { type: 'polar' }, series: [...] }).

Why does my polar / radar chart render as a line chart?

The chart type was not registered. KatuCharts logs "KatuCharts: unknown series type " ", falling back to line" and draws a line chart rather than throwing. Import the module the type belongs to — for example `import 'katucharts.js/bio';` — before creating the chart.

Why do I get "Cannot read properties of null (reading 'appendChild')"?

The container element does not exist when the chart is created. Create the chart after the element is in the DOM: in React that means inside useEffect, not during render.

Why is the chart rendering with zero height?

The container has no height. A div with no content collapses to zero. Give it a height in CSS, or pass `chart: { height: 400 }` in the options.

Gauge / Polar

Polar / Radar

type: 'polar'

Radial coordinate chart; points map to angle (category) and radius (value). Set chart.polar: true.

Edit the JSON on the right and press Run (or ⌘/Ctrl + Enter) — data, titles, categories and colors all update live.

Live

Polar / Radar

Edit · JSON

Data format

[value, value, …] · [{ name, y }]

Data shape

The JSON you pass inside the chart — drop it straight into your series.

series: [
  { name: 'katucharts', data: [92, 95, 88, 90, 84, 96] },
  { name: 'Legacy lib', data: [70, 55, 62, 75, 80, 58] }
]

Example

import KatuCharts from 'katucharts.js';

KatuCharts.chart('container', {
  chart: { type: 'polar' },
  chart: { polar: true },
  xAxis: { categories: ['Speed', 'Theming', 'A11y', 'Exports', 'Docs', 'DX'] },
  yAxis: { min: 0, max: 100 },
  series: [
    { name: 'katucharts', data: [92, 95, 88, 90, 84, 96] },
    { name: 'Legacy lib', data: [70, 55, 62, 75, 80, 58] }
  ]
});

Type-specific options

Option	Description
`chart.polar: true`	Activate the polar coordinate system.
`connectEnds`	Connect the last point to the first (default true).
`pointPlacement`	'on' \| 'between' \| pixel offset.

Variations

Filled radar

Use series type 'area' for a filled radar with translucent overlap.

KatuCharts.chart('container', {
  chart: { type: 'polar' },
  chart: { polar: true },
  xAxis: { categories: ['Speed','Theming','A11y','Exports','Docs','DX'] },
  yAxis: { min: 0, max: 100 },
  series: [
    { type: 'area', name: 'katucharts', data: [92,95,88,90,84,96], fillOpacity: 0.4 },
    { type: 'area', name: 'Legacy lib', data: [70,55,62,75,80,58], fillOpacity: 0.4 }
  ]
});

Common errors

Why does my polar / radar chart render as a line chart?: The chart type was not registered. KatuCharts logs "KatuCharts: unknown series type "<type>", falling back to line" and draws a line chart rather than throwing. Import the module the type belongs to — for example `import 'katucharts.js/bio';` — before creating the chart.
Why do I get "Cannot read properties of null (reading 'appendChild')"?: The container element does not exist when the chart is created. Create the chart after the element is in the DOM: in React that means inside useEffect, not during render.
Why is the chart rendering with zero height?: The container has no height. A div with no content collapses to zero. Give it a height in CSS, or pass `chart: { height: 400 }` in the options.

FAQ

How do I create a polar / radar chart in JavaScript?: Install with `npm install katucharts.js`, then call KatuCharts.chart(container, { chart: { type: 'polar' }, series: [...] }).
Why does my polar / radar chart render as a line chart?: The chart type was not registered. KatuCharts logs "KatuCharts: unknown series type "<type>", falling back to line" and draws a line chart rather than throwing. Import the module the type belongs to — for example `import 'katucharts.js/bio';` — before creating the chart.
Why do I get "Cannot read properties of null (reading 'appendChild')"?: The container element does not exist when the chart is created. Create the chart after the element is in the DOM: in React that means inside useEffect, not during render.
Why is the chart rendering with zero height?: The container has no height. A div with no content collapses to zero. Give it a height in CSS, or pass `chart: { height: 400 }` in the options.

Common options (color, visible, marker, dataLabels, animation, events, zones…) apply to every type — see Configuration → series. See it rendered in the gallery.