inedpl_c |

## Procedurevoid inedpl_c ( SpiceDouble a, SpiceDouble b, SpiceDouble c, ConstSpicePlane * plane, SpiceEllipse * ellipse, SpiceBoolean * found ) ## AbstractFind the intersection of a triaxial ellipsoid and a plane. ## Required_ReadingELLIPSES PLANES ## KeywordsELLIPSE ELLIPSOID GEOMETRY MATH ## Brief_I/OVariable I/O Description -------- --- -------------------------------------------------- a I Length of ellipsoid semi-axis lying on the x-axis. b I Length of ellipsoid semi-axis lying on the y-axis. c I Length of ellipsoid semi-axis lying on the z-axis. plane I Plane that intersects ellipsoid. ellipse O Intersection ellipse, when found is SPICETRUE. found O Flag indicating whether ellipse was found. ## Detailed_Inputa, b, c are the lengths of the semi-axes of a triaxial ellipsoid. The ellipsoid is centered at the origin and oriented so that its axes lie on the x, y and z axes. a, b, and c are the lengths of the semi-axes that point in the x, y, and z directions respectively. plane is a CSPICE plane. ## Detailed_Outputellipse is the CSPICE ellipse formed by the intersection of the input plane and ellipsoid. ellipse will represent a single point if the ellipsoid and plane are tangent. If the intersection of the ellipsoid and plane is empty, ellipse is not modified. found is SPICETRUE if and only if the intersection of the ellipsoid and plane is non-empty. ## ParametersNone. ## Exceptions1) If any of the lengths of the semi-axes of the input ellipsoid are non-positive, the error SPICE(DEGENERATECASE) is signalled. ellipse is not modified. found is set to SPICEFALSE. 2) If the input plane in invalid, the error will be diagnosed by routines called by this routine. ellipse is not modified. found is set to SPICEFALSE. 3) If the input plane and ellipsoid are very nearly tangent, roundoff error may cause this routine to give unreliable results. 4) If the input plane and ellipsoid are precisely tangent, the intersection is a single point. In this case, the output ellipse is degenerate, but found will still have the value SPICETRUE. You must decide whether this output makes sense for your application. ## FilesNone. ## ParticularsAn ellipsoid and a plane can intersect in an ellipse, a single point, or the empty set. ## Examples1) Suppose we wish to find the limb of a body, as observed from location loc in body-fixed coordinates. The CSPICE routine edlimb_c solves this problem. Here's how ## RestrictionsNone. ## Literature_ReferencesNone. ## Author_and_InstitutionN.J. Bachman (JPL) ## Version-CSPICE Version 1.0.5, 06-FEB-2003 (EDW) Corrected a typo in the header documentation, input variable 'ellipse' not 'ellips' -CSPICE Version 1.0.0, 13-JUN-1999 (NJB) ## Index_Entriesintersection of ellipsoid and plane |

Wed Apr 5 17:54:37 2017