User Manual 3.3 Ellipsoids

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Definition

An ellipsoid is a closed quadric surface that is the three dimensional analogue of an ellipse. Assuming the XYZ coordinate system is such that the ellipsoid is centered and axis-aligned, the ellipsoids equation is given by:

S={(x,y,z)R3/x2a2+y2b2+z2c2=1}
Ellipsoid.PNG

a,b and c are called the semi axes of the ellipsoid.

Implementation

The Ellipsoid object in the SIRIUS library implements the Ellipsoid interface. Please refer to the Javadoc for a complete list of public methods.

Instantiation

In order to instantiate an ellipsoid, the user must specify the ellipsoids' center, it's axis of revolution, X-axis, and all three semi-axis a,b

and c
. For example :

// Spheroid parameters
Vector3D position = new Vector3D(0, 0, 0);
Vector3D revAxis = new Vector3D(0, 0, 1);
Vector3D xAxis = new Vector3D(1, 0, 0);
double a = 2.0;
double c = 1.5;
double c = 1.0;
// The ellipsoid itself
Ellipsoid myEllipsoid = new Ellipsoid(position, revAxis, xAxis, a, b, c);

Usage

Please refer to the [MAT_GEO_Home#HInteractions Interactions with other geometrical objects section] for methods inherited from the Shape interface.