Editing Step function (section)

==Examples==
[[Image:Dirac distribution CDF.svg|325px|thumb|The [[Heaviside step function]] is an often-used step function.]]
* A [[constant function]] is a trivial example of a step function. Then there is only one interval, <math>A_0=\mathbb R.</math>
* The [[sign function]] {{math|sgn(''x'')}}, which is −1 for negative numbers and +1 for positive numbers, and is the simplest non-constant step function.
* The [[Heaviside step function|Heaviside function]] {{math|''H''(''x'')}}, which is 0 for negative numbers and 1 for positive numbers, is equivalent to the sign function, up to a shift and scale of range (<math>H = (\sgn + 1)/2</math>). It is the mathematical concept behind some test [[Signal (electronics)|signals]], such as those used to determine the [[step response]] of a [[dynamical system (definition)|dynamical system]].
[[File:Rectangular function.svg|thumb|The [[rectangular function]], the next simplest step function.]]
* The [[rectangular function]], the normalized [[boxcar function]], is used to model a unit pulse.

===Non-examples===
* The [[integer part]] function is not a step function according to the definition of this article, since it has an infinite number of intervals. However, some authors<ref name=bachman_narici_beckenstein>{{Cite book | author=Bachman, Narici, Beckenstein | title=Fourier and Wavelet Analysis | publisher=Springer, New York, 2000 | isbn=0-387-98899-8 | chapter =Example 7.2.2| date=5 April 2002 }}</ref> also define step functions with an infinite number of intervals.<ref name=bachman_narici_beckenstein />