represents an infinite numerical quantity whose direction in the complex plane is unknown.
DirectedInfinity [z]
represents an infinite numerical quantity that is a positive real multiple of the complex number z.
DirectedInfinity
represents an infinite numerical quantity whose direction in the complex plane is unknown.
DirectedInfinity [z]
represents an infinite numerical quantity that is a positive real multiple of the complex number z.
Details
- You can think of DirectedInfinity [z] as representing a point in the complex plane reached by starting at the origin and going an infinite distance in the direction of the point z.
- The following conversions are made:
-
-Infinity DirectedInfinity [-1]
- Certain arithmetic operations are performed on DirectedInfinity quantities.
- In OutputForm , DirectedInfinity [z] is printed in terms of Infinity , and DirectedInfinity [] is printed as ComplexInfinity .
Examples
open all close allBasic Examples (3)
Use as an expansion point and direction:
Use as an integration limit:
Use as a limiting point:
Scope (6)
Some directions have a special StandardForm :
Use inf to enter ∞:
Use Infinity as an alternative input form:
Multiplying by a number changes the direction:
Unspecified or Indeterminate direction represents ComplexInfinity :
Finite or symbolic quantities are absorbed:
Extended arithmetic with infinite quantities:
In this case the result depends on the directions x and y:
Operations that cannot be unambiguously defined produce Indeterminate :
In this case the result depends on the growth rates of the numerator and denominator:
Use in mathematical functions:
The value in different directions may vary:
Applications (2)
Integrate along a line from the origin with direction :
Asymptotics of the LogGamma function at DirectedInfinity [z]:
Plot asymptotic value compared to function value in different directions:
Properties & Relations (3)
Simplify and FullSimplify can generate infinities:
A nested DirectedInfinity reduces to one DirectedInfinity :
DirectedInfinity [] is not a number:
Possible Issues (3)
Symbolic quantities might get lost in operations:
The Accuracy and Precision for DirectedInfinity refer to the direction argument:
Simplifications performed by the Wolfram Language assume symbols to represent numbers:
Tech Notes
Related Guides
Related Links
History
Introduced in 1988 (1.0)
Text
Wolfram Research (1988), DirectedInfinity, Wolfram Language function, https://reference.wolfram.com/language/ref/DirectedInfinity.html.
CMS
Wolfram Language. 1988. "DirectedInfinity." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/DirectedInfinity.html.
APA
Wolfram Language. (1988). DirectedInfinity. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/DirectedInfinity.html
BibTeX
@misc{reference.wolfram_2025_directedinfinity, author="Wolfram Research", title="{DirectedInfinity}", year="1988", howpublished="\url{https://reference.wolfram.com/language/ref/DirectedInfinity.html}", note=[Accessed: 23-November-2025]}
BibLaTeX
@online{reference.wolfram_2025_directedinfinity, organization={Wolfram Research}, title={DirectedInfinity}, year={1988}, url={https://reference.wolfram.com/language/ref/DirectedInfinity.html}, note=[Accessed: 23-November-2025]}