Piecewise
Details
- The condi are typically inequalities such as .
- The condi are evaluated in turn, until one of them is found to yield True .
- If all preceding condi yield False , then the vali corresponding to the first condi that yields True is returned as the value of the piecewise function.
- If any of the preceding condi do not literally yield False , the Piecewise function is returned in symbolic form.
- Only those vali explicitly included in the returned form are evaluated.
- Elements of the form {vali,False } are dropped, as are all elements after the first {vali,True }.
- Piecewise [conds] automatically evaluates to Piecewise [conds,0].
- Piecewise can be used in such functions as Integrate , Minimize , Reduce , DSolve , and Simplify , as well as their numeric analogs.
- Piecewise [{{v1,c1},{v2,c2},…}] can be input in the form
v1 c1v2 c2…. The piecewise operator can be entered as pw or \[Piecewise] . The grid of values and conditions can be constructed by first entering , then using and .
- In StandardForm and TraditionalForm , Piecewise [{{v1,c1},{v2,c2},…}] is normally output using a brace, as in
v1 c1v2 c2….
Examples
open all close allBasic Examples (3)
Set up a piecewise function with different pieces below and above zero:
Find the derivative of a piecewise function:
Use pw to enter and and then TemplateBox[{ctrl, return}, Key1, BaseStyle -> {ExampleText, FontWeight -> Plain, FontFamily -> Source Sans Pro}] for each additional piecewise case:
Scope (12)
Define a piecewise function:
Evaluate it at specific points:
Plot it:
Refine it under assumptions:
Automatic simplification of Piecewise functions:
Remove unreachable cases:
Remove False conditions:
Merge cases with the same values:
If values are not specified in a region, they are assumed to be zero:
This specifies that the default value should be 1:
Compute limits of piecewise functions:
Compute the limit in the direction of the positive imaginary axis:
Compute the series of a piecewise function:
Integrate a piecewise function:
Integration constants are chosen to make the result continuous:
Compute a definite integral of a piecewise function:
Laplace transform of a piecewise function:
Solve a piecewise differential equation:
Reduce a piecewise equation:
Integrating an implicitly piecewise integrand can give an explicit Piecewise result:
Symbolic minimization can give piecewise functions:
Applications (1)
Compute the volume of an ellipsoid:
Properties & Relations (11)
PiecewiseExpand converts nested piecewise functions into a single piecewise function:
Min , Max , UnitStep , and Clip are piecewise functions of real arguments:
Abs , Sign , and Arg are piecewise functions when their arguments are assumed to be real:
KroneckerDelta and DiscreteDelta are piecewise functions of complex arguments:
Boole is a piecewise function of a Boolean argument:
If , Which , and Switch can be interpreted as piecewise functions:
Convert Floor , Ceiling , Round , IntegerPart , and FractionalPart for finite ranges:
Convert Mod and Quotient when the number of cases is finite:
UnitBox and UnitTriangle are piecewise functions of real arguments:
Convert SquareWave , TriangleWave , and SawtoothWave for finite ranges:
BernsteinBasis and BSplineBasis are piecewise functions of real arguments:
Possible Issues (1)
Derivatives are computed piece-by-piece, unless the function is univariate in a real variable:
To specify that is real, use inequalities in the first condition:
This function is discontinuous at :
Tech Notes
Related Guides
Related Links
History
Introduced in 2004 (5.1) | Updated in 2008 (7.0)
Text
Wolfram Research (2004), Piecewise, Wolfram Language function, https://reference.wolfram.com/language/ref/Piecewise.html (updated 2008).
CMS
Wolfram Language. 2004. "Piecewise." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2008. https://reference.wolfram.com/language/ref/Piecewise.html.
APA
Wolfram Language. (2004). Piecewise. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Piecewise.html
BibTeX
@misc{reference.wolfram_2025_piecewise, author="Wolfram Research", title="{Piecewise}", year="2008", howpublished="\url{https://reference.wolfram.com/language/ref/Piecewise.html}", note=[Accessed: 05-December-2025]}
BibLaTeX
@online{reference.wolfram_2025_piecewise, organization={Wolfram Research}, title={Piecewise}, year={2008}, url={https://reference.wolfram.com/language/ref/Piecewise.html}, note=[Accessed: 05-December-2025]}