not-a-number

Computing Dictionary

Not-a-Number definition

mathematics
(NaN) An IEEE floating point representation for the result of a numerical operation which cannot return a valid number value. A NaN can result from multiplying an infinity by a zero, or from subtracting one infinity from another [what else?].
NaN is encoded as a special bit pattern [what pattern?] which would otherwise represent a floating-point number. It is used to signal error returns where other mechanisms are not convenient, e.g. a hardware floating-point unit and to allow errors to propagate through a calculation.
Similar bit patterns represent positive and negative overflow and underflow and the positive and negative infinities resulting from division by zero.
Bit patterns (http://psc.edu/general/software/packages/ieee/ieee.html).
[ANSI/IEEE Std 754-1985].
[Correct?]
(2001-04-01)
The Free On-line Dictionary of Computing, © Denis Howe 2010 http://foldoc.org
Cite This Source
Explore Dictionary.com
Previous Definition: not-
Next Definition: not-circuit
Words Near: Not-a-Number
More from Thesaurus.com
Synonyms and Antonyms for Not-a-Number
More from Reference.com
Search for articles containing Not-a-Number
More from Dictionary.com Translator
Dictionary.com Word FAQs

Dictionary.com presents 366 FAQs, incorporating some of the frequently asked questions from the past with newer queries.

Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature