% This is generated by ESQL's StSimplifyTests. Do not edit it. See docs/reference/query-languages/esql/README.md for how to regenerate it.

### Diagrams

**Low tolerance keeps almost every vertex**

With a small tolerance, only collinear or near-collinear vertices are removed.

:::{image} ../../../../../images/generated/x-pack-esql/functions/st_simplify_low_tolerance.svg
:alt: Low tolerance keeps almost every vertex
:class: text-center
:::

**Mid tolerance smooths out the bumps**

A tolerance of `0.2` is large enough to remove the small dents along each edge, leaving the underlying square.

:::{image} ../../../../../images/generated/x-pack-esql/functions/st_simplify_mid_tolerance.svg
:alt: Mid tolerance smooths out the bumps
:class: text-center
:::

**Simplifying a circle with tolerance 0.5**

Higher tolerances drop more vertices and the circle becomes a rough polygon.

:::{image} ../../../../../images/generated/x-pack-esql/functions/st_simplify_circle_quarter.svg
:alt: Simplifying a circle with tolerance 0.5
:class: text-center
:::

**Simplifying a circle to an octagon**

Tolerance `1.0` reduces the circle to a regular octagon.

:::{image} ../../../../../images/generated/x-pack-esql/functions/st_simplify_circle_octagon.svg
:alt: Simplifying a circle to an octagon
:class: text-center
:::

**Simplifying a coastline at moderate tolerance**

France's coastline simplified at tolerance `0.1` (roughly 10 km). Small bays and peninsulas survive but the coastline is noticeably smoother.

:::{image} ../../../../../images/generated/x-pack-esql/functions/st_simplify_france_medium.svg
:alt: Simplifying a coastline at moderate tolerance
:class: text-center
:::

**Simplifying a coastline at coarse tolerance**

France's coastline simplified at tolerance `0.5` (roughly 50 km). Only the high-level shape of the country remains.

:::{image} ../../../../../images/generated/x-pack-esql/functions/st_simplify_france_coarse.svg
:alt: Simplifying a coastline at coarse tolerance
:class: text-center
:::

