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octant

 
Dictionary: oc·tant   (ŏk'tənt) pronunciation
n.
  1. One eighth of a circle.
    1. A 45° arc.
    2. The area enclosed by two radii at a 45° angle and the intersected arc.
  2. An instrument based on the principle of the sextant but employing only a 45° angle, used as an aid in navigation.
  3. Astronomy. The position of a celestial body when it is separated from another by a 45° angle.
  4. One of eight parts into which three-dimensional space is divided by three usually perpendicular coordinate planes.

[Latin octāns, octant-, from octō, eight.]

octantal oc·tan'tal (ŏk-tăn'təl) adj.

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n. an obsolete instrument in the form of a graduated eighth of a circle, used in astronomy and navigation.

See the Introduction, Abbreviations and Pronunciation for further details.

WordNet: octant
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Note: click on a word meaning below to see its connections and related words.

The noun has one meaning:

Meaning #1: a measuring instrument for measuring angles to a celestial body; similar to a sextant but with 45 degree calibration


Wikipedia: Octant
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An octant is one of eight divisions.

Contents

Octant in the plane

An octant is one of 8 parts of the two-dimensional Euclidean coordinate system.

Traditionally wind direction is given as one of the 8 octants (N, NE, E, SE, S, SW, W, NW) because that is more accurate than merely giving one of the 4 quadrants, and the wind vane typically does not have enough accuracy to bother with more precise indication.

Octant in three-dimensional space

An octant is one of the eight divisions of a Euclidean three-dimensional coordinate system. It is similar to the two-dimensional quadrant and the one-dimensional ray.

The n-dimensional generalization is the orthant.

Octant order

Usually, the octant with all three positive coordinates is referred to as the first octant. Nevertheless there is no generally used naming convention for the other seven octants. first octant (+, +, +) top-back-right (−, +, +) top-back-left (−, −, +) top-front-left (+, −, +) bottom-front-left (+, −, −) bottom-back-left (−, −, −) bottom-back-right (−, +, −) bottom-front-right (+, +, −)

See also

External links


Best of the Web: octant
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Some good "octant" pages on the web:


Math
mathworld.wolfram.com
 
 
 
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Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.  Read more
US Military Dictionary. The Oxford Essential Dictionary of the U.S. Military. Copyright © 2001, 2002 by Oxford University Press, Inc. All rights reserved.  Read more
WordNet. WordNet 1.7.1 Copyright © 2001 by Princeton University. All rights reserved.  Read more
Wikipedia. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article "Octant" Read more

 

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