Wiktionary
n. (context analysis English) The set of values ''x'' for which a real-valued function ''f''(''x'') is equal to a given constant. vb. (business) To establish a baseline of mutual understanding
Wikipedia
In mathematics, a level set of a real-valued function f of n real variables is a set of the form
L(f) = {(x, ⋯, x) ∣ f(x, ⋯, x) = c} ,that is, a set where the function takes on a given constant value c.
When the number of variables is two, a level set is generically a curve, called a level curve, contour line, or isoline. So a level curve is the set of all real-valued solutions of an equation in two variables x and x. When n = 3, a level set is called a level surface (see also isosurface), and for higher values of n the level set is a level hypersurface. So a level surface is the set of all real-valued roots of an equation in three variables x, x and x, and a level hypersurface is the set of all real-valued roots of an equation in n (n > 3) variables.
A level set is a special case of a fiber.
In computer science a level set data structure is designed to represent discretely sampled dynamic level sets functions.
A common use of this form of data structure is in efficient image rendering. The underlying method constructs a signed distance field that extends from the boundary, and can be used to solve the motion of the boundary in this field.
Usage examples of "level set".
Nature has arranged that most flies will become food for birds and frogs, and she has also arranged that most souls will not achieve salvation but will, even though they don't die like the flies, fail to reach the level set for them.
The light settled to a level set by the burning wag, and the only sound was the crackling of flames.
Forests of suits ranging from blue to gray to black, a parade of shirts in tones of white or the most delicate pastels, hung in precise order on a two-level set of bars.