Nodes As Functions
Each of these nodes can also be called a function. However, this type of function (i.e. a node in a parse tree) is not the same as a function in mathematics or computer programming. A function in mathematics takes in zero or more inputs and returns a value.
In parse trees, a function can be a true mathematical function which "uses" its child nodes as inputs, and returns a single output to its parent. More often, however, a node in a parse tree is a static symbol such as a number, letter, or word.
The use of parse tree functions is highly dependent on the area which is using it. In the branch of evolutionary computation called genetic programming, for instance, tree functions are quite often (but not exclusively) used as mathematical-style function. In linguistics and linguistic theory, tree functions are never mathematical functions, except in certain areas of computational linguistics.
Read more about this topic: Terminal Function
Famous quotes containing the words nodes and/or functions:
“There are characters which are continually creating collisions and nodes for themselves in dramas which nobody is prepared to act with them. Their susceptibilities will clash against objects that remain innocently quiet.”
—George Eliot [Mary Ann (or Marian)
“Let us stop being afraid. Of our own thoughts, our own minds. Of madness, our own or others’. Stop being afraid of the mind itself, its astonishing functions and fandangos, its complications and simplifications, the wonderful operation of its machinery—more wonderful because it is not machinery at all or predictable.”
—Kate Millett (b. 1934)