英和和英

語源

From ellipse +‎ -oid.

発音

• (英国発音) IPA: /ɪˈlɪp.sɔɪd/
• (米国発音) IPA: /ɪˈlɪp.sɔɪd/, /əˈlɪp.sɔɪd/, /iˈlɪp.sɔɪd/
• (General Australian) IPA: /əˈlɪp.soɪd/, /ɪˈlɪp.soɪd/

名詞

ellipsoid (plural ellipsoids)

1. (mathematics, geometry) A surface, all of whose cross sections are elliptic or circular (including the sphere), that generalises the ellipse and in Cartesian coordinates (x, y, z) is a quadric with equation x/a + y/b + z/c = 1.
   • 2002, John Michael Hollas, Basic Atomic and Molecular Spectroscopy, page 133:

     Polarizability can be imagined as a three-dimensional ellipsoid centred on the centre of the molecule, as shown in Figure 10.4.

   • 2004, Alfred Leick, GPS Satellite Surveying, 3rd edition, page 367:

     Because only ellipsoids of rotation have been adopted in practical geodesy and surveying and triaxial ellipsoids have been limited to theoretical studies, we will use the term ellipsoid for brevity to mean ellipsoid of rotation.

   • 2010, Jan Van Sickle, Basic GIS Coordinates, 2nd edition, page 73:

     As mentioned before, modern geodetic datums rely on the surfaces of geocentric ellipsoids to approximate the surface of the earth.

2. (geography) Such a surface used as a model of the shape of the earth.

   Here the geoid is thirty meters below the ellipsoid.

使用する際の注意点

• The general case, with semiaxes a, b and c all different, is a triaxial ellipsoid (more rarely, scalene ellipsoid). If two are the same, say b = c, the result is an ellipsoid of revolution, which may be oblate (if a < b) or prolate (a > b). The degenerate case a = b = c is a sphere. An ellipsoid of revolution is also called a spheroid.

上位語

• quadric surface, quadric

派生語

関連する語

• ellipsoidal
• subellipsoid

参考

• geoid

形容詞

ellipsoid (comparative more ellipsoid, superlative most ellipsoid)

1. Shaped like an ellipse; elliptical.
2. (mathematics) Of or pertaining to an ellipse; elliptic.
3. (botany) Having the tridimensional shape of an ellipse rotated on its long axis.

関連する語

• ellipsoidal
• globoid
• ovoid

参考

• globose
• oblong