---
tag: 0B2RZ0778N
kind: concept
name: Level set
aliases: [level-curve, level-surface, fibre-of-a-function]
msc: [26B99]
uses: [0JPCHTXWG0]
sources:
  - url: https://en.wikipedia.org/wiki/Level_set
    locator: lead section
same_as:
  wikidata: Q126955
  wikipedia: Level set
---

## Summary

A level set of a real-valued [[function of several variables|0JPCHTXWG0]] is a set of points of the domain. At these points, the function takes one given value.
For a function of two variables a level set is often a curve, and for a function of three variables it is often a surface.