Recursion


 
 
Recursion

In mathematics and computer science, recursion is a particular way of specifying (or constructing) a class of objects (or an object from a certain class) with the help of a reference to other objects of the class: a recursive definition defines objects in terms of the already defined objects of the class.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

For example, the following is a recursive definition of person's ancestors:

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

  • One's parents are one's ancestors (base case);
  • The parents of any ancestor are also ancestors of the person under consideration (recursion step).
  • For instance, your ancestors are:

    ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

  • your parents, and
  • your parents' parents (= grandparents), and
  • your grandparents' parents, and
  • everyone else you get by successively adding ancestors
  • It is convenient to think that a recursive definition defines objects in terms of "previously defined" objects of the class to define.

    ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

    Definitions such as these are ubiquitous in mathematics. In fact, the formal definition of natural numbers is very similar: 0 is a natural number, and each natural number has a successor, which is also a natural number.


     

    Computer science: Computer science (abbreviated CS or compsci) encompasses a variety of topics that relates to computation, like abstract analysis of algorithms, formal grammars, and subjects such as programming languages, program design, software, computer hardware, artificial intelligence, and numerical analysis. B...


    Recursion related Images and Photos (experimental)

    Recursion
    Recursion
    Andre Curse - A Storybook about Recursion
    Andre Curse - A Storybook about Recursion

~ Table of Content ~

Introduction
An example
Recursion in mathematics
Recursion in computing
Recursion in language
Recurrence relations or algorithms
Recursively defined sets
Recursively defined functions
3 * f (2)
3 * 2 * f (2 - 1)
3 * 2 * f (1)
3 * 2 * 1 * f (1 - 1)
3 * 2 * 1 * f (0)
3 * 2 * 1 * 1
 
FR: Récursivité


 

~ Related Subjects ~

Computer science (2) - Software (1) - Program (1) - Computer hardware (1) - Numerical analysis (1) - Artificial intelligence (1) - Abbreviated (1) - Mathematics (1) - Algorithms (1) - Programming language (1) - Formal grammar (1) -
 

~ Community ~

History Forum
Come and discuss about History, Civilizations, Historical Events and Figures
History Web-Ring
A community of sites, blogs and forums dedicated to History. Do not hesitate to submit your site.