elasticsearch/docs/reference/esql/functions/tau.asciidoc

[[esql-tau]]
=== `TAU`
[.text-center]
image::esql/functions/signature/tau.svg[Embedded,opts=inline]

The https://tauday.com/tau-manifesto[ratio] of a circle's circumference to its radius.

[source.merge.styled,esql]
----
include::{esql-specs}/math.csv-spec[tag=tau]
----
[%header.monospaced.styled,format=dsv,separator=|]
|===
include::{esql-specs}/math.csv-spec[tag=tau-result]
|===