Search results
Results from the WOW.Com Content Network
An ellipse (red) obtained as the intersection of a cone with an inclined plane. Ellipse: notations Ellipses: examples with increasing eccentricity. In mathematics, an ellipse is a plane curve surrounding two focal points, such that for all points on the curve, the sum of the two distances to the focal points is a constant.
For example, on a triaxial ellipsoid, the meridional eccentricity is that of the ellipse formed by a section containing both the longest and the shortest axes (one of which will be the polar axis), and the equatorial eccentricity is the eccentricity of the ellipse formed by a section through the centre, perpendicular to the polar axis (i.e. in ...
An ellipse in general position can be expressed as = + = + + as the parameter t varies from 0 to 2 π . Here ( X c , Y c ) is the center of the ellipse, and φ is the angle between the x -axis and the major axis of the ellipse.
One dimensional position-momentum plot, showing the beam ellipse described in terms of the Courant–Snyder parameters. In accelerator physics, the Courant–Snyder parameters (frequently referred to as Twiss parameters or CS parameters) are a set of quantities used to describe the distribution of positions and velocities of the particles in a beam. [1]
A typical example might involve an integration over all pairs of vectors and that sum to a fixed vector = +, where the integrand was a function of the vector lengths | | and | |. (In such a case, one would position r {\displaystyle \mathbf {r} } between the two foci and aligned with the x {\displaystyle x} -axis, i.e., r = 2 a x ...
Those integrals are in turn named elliptic because they first were encountered for the calculation of the arc length of an ellipse. Important elliptic functions are Jacobi elliptic functions and the Weierstrass ℘-function. Further development of this theory led to hyperelliptic functions and modular forms.
Elliptical distributions are defined in terms of the characteristic function of probability theory. A random vector X {\displaystyle X} on a Euclidean space has an elliptical distribution if its characteristic function ϕ {\displaystyle \phi } satisfies the following functional equation (for every column-vector t {\displaystyle t} )
The semi-minor axis of an ellipse runs from the center of the ellipse (a point halfway between and on the line running between the foci) to the edge of the ellipse. The semi-minor axis is half of the minor axis. The minor axis is the longest line segment perpendicular to the major axis that connects two points on the ellipse's edge.