Reference · Framing, geometry and quiz tools
regionCentrefunction
The middle of a region, for zooming to whatever somebody just chose: where it is drawn, not where it is. Okinawa is drawn in a box in the Sea of Japan and Alaska in one below the lower forty-eight, so centring on their true positions would take the reader to open sea; Tokyo, whose far islands are boxed, is centred on the Tokyo left in place.
Import it
import { regionCentre } from "@johnmorrisdotca/chizu";Definition
function regionCentre(map: Frameable, code: string | number | null): { x: number; y: number; } | nullParameters
| Name | Type | Description |
|---|---|---|
map | Frameable | The native map or map fields required by this signature; coordinates and region codes belong to its canvas. |
code | string | number | null | The native region or country code; null clears a region selection where accepted. |
Returns
{ x: number; y: number; } | null
The region’s drawn centre in native map units, or null for a null or unknown region code.
Examples
import { loadDivisions } from "@johnmorrisdotca/chizu/load";
import { regionCentre } from "@johnmorrisdotca/chizu";
const japan = (await loadDivisions("jp"))!;
// Okinawa is drawn in boxes, so its centre is where its main islands are drawn, in the first.
console.log(regionCentre(japan, "47"));
// { x: 315, y: 560 }{ x: 315, y: 560 }What it prints (run when this page was built)