Polar area

Sector radius carries the value.

import { PolarArea } from "diagrammatic";

A Nightingale rose for a city hospital: twenty-four hours around the clock, sector area as volume. The form shows a daily cycle.

Illustrative data. ED trauma desk, 2024. n = 639 arrivals.

fig. 19.1 · Trauma arrivals by hour, one year

Arrivals reach 52 at 15h and peak at 61 at 16h, then fall to 48 at 17h. The lowest count is 8 at 04h. The tooltip gives the count behind each sector's area.

Sixteen compass sectors. Sector area represents measured hours of wind from each direction. This is the same PolarArea as the trauma clock, pointed at a compass.

Illustrative data. Harbour anemometer, 2024. Hours per 22.5° sector.

fig. 19.2 · Wind rose, one harbour year

SW is the largest sector at 980 hours, followed by SSW at 890. NE is the smallest at 140 hours. Adjacent sectors show the broad south-west concentration.

Use it for: Cyclic categories with a dramatic shape, the Nightingale rose.
Watch out: Area grows with the square of radius; readers overestimate the big sectors.