---
id: "packages/active-charts/all-exports/zones"
title: "Zones"
description: "LineZoneRange, SeriesZones, ZoneBoundary, ZoneRange: generated from the source of active-charts."
url: "/packages/active-charts/all-exports/zones"
locale: "en"
revision: "g0mvjxwj5c-88bdbe1c:zones"
---

# Zones

Exported by `@workspace/active-charts`. Generated from the package source; part of [the index of every export](/packages/active-charts/all-exports).

## Types

**LineZoneRange**

```ts
type LineZoneRange = Omit<ZoneRange, 'fill'>;
```

A line's zone range: a line has no fill.

**SeriesZones**

```ts
interface SeriesZones<TRange extends LineZoneRange = ZoneRange> {
  axis?: 'x' | 'y';
  ranges: readonly TRange[];
}
```

The zones of a line or an area series (T3): its paint split where the
DRAWN path crosses a boundary, on the curve as drawn (linear, monotone,
Catmull-Rom, the steps), on a log axis as on a linear one; never at the
next data point.

- `axis: 'y'` (default) splits by value: below a target, negative
values. On an area the filled region is split by height too (the fill
below 100 in one paint, above it in another).
- `axis: 'x'` splits by position: history and forecast. On a number,
log, sqrt, time or ordinal-time x axis; not on a category axis.

Ranges are read in the given order; a value in two ranges belongs to the
earlier (development diagnostic), a value in none keeps the series paint.
A range that cannot be read (`from` at or above `to`, a boundary that is
not a finite number or date) is ignored with a diagnostic. A point marker
takes the zone of its own value; an explicit marker paint wins. A stacked
area takes x zones only. Missing values stay gaps. Under forced colours
the zone colours give way to the series' system colour and the dash
remains. No legend entry and no CSV column.

**ZoneBoundary**

```ts
type ZoneBoundary = number | Date | IsoDateString;
```

A boundary of a zone, in the value type of its axis: a number on a value
axis or a numeric x axis, a date (`Date`, an ISO string or epoch
milliseconds, as the data itself) on a time or ordinal-time x axis.

**ZoneRange**

```ts
interface ZoneRange {
  from?: ZoneBoundary;
  to?: ZoneBoundary;
  stroke?: string;
  fill?: string;
  lineDash?: number[];
  name?: string;
}
```

One range of a series' zones (T3): the values from `from` (inclusive) up
to `to` (exclusive), the class rule of the heatmap's named classes. An
absent `from` reaches every lower value, an absent `to` every higher one.

A zone changes paint only: `stroke`, `fill` (an area's) and `lineDash`;
what it leaves out keeps the series' own. Never width, opacity, gradient
shape, marker shape or size, curve or animation.