cspice_inedpl |
|||

## AbstractCSPICE_INEDPL calculates the intercept of a triaxial ellipsoid and a plane. ## I/OGiven: a [1,1] = size(a); double = class(a) b [1,1] = size(b); double = class(b) c [1,1] = size(c); double = class(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 respectively point in the x, y, and z directions. plane a structure describing a SPICE plane. The intersection of 'plane' and the ellipsoid is sought. [1,1] = size(plane); struct = class(plane) The structure has the fields: normal: [3,1] = size(normal); double = class(normal) constant: [1,1] = size(constant); double = class(constant) the call: [ ellipse, found ] = ## ExamplesAny numerical results shown for this example may differ between platforms as the results depend on the SPICE kernels used as input and the machine specific arithmetic implementation. Use the meta-kernel shown below to load the required SPICE kernels. KPL/MK This meta-kernel is intended to support operation of SPICE example programs. The kernels shown here should not be assumed to contain adequate or correct versions of data required by SPICE-based user applications. In order for an application to use this meta-kernel, the kernels referenced here must be present in the user's current working directory. The names and contents of the kernels referenced by this meta-kernel are as follows: File name Contents --------- -------- de421.bsp Planetary ephemeris pck00009.tpc Planet orientation and radii naif0009.tls Leapseconds \begindata KERNELS_TO_LOAD = ( '/kernels/gen/lsk/naif0009.tls' '/kernels/gen/spk/de421.bsp' '/kernels/gen/pck/pck00009.tpc' ) \begintext % % Give a position relative to an ellipsoid, calculate % the terminator on the ellipsoid as seen from the position. % As an example, use the view of Earth from the sun. % % % Standard SPK, LSK, PCK files. % cspice_furnsh( 'standard.tm' ) % % Define the time to calculate the terminator, the reference % frame, and the light time correction. % TIME = 'Oct 31 2002, 12:55:00 PST'; FRAME = 'J2000'; CORR = 'LT+S'; % % Convert the date string to ephemeris time. % et = cspice_str2et( TIME ); % % calculate the position of Earth wrt the Sun. % [pos, ltime] = cspice_spkpos( 'EARTH', et, FRAME, CORR, 'SUN' ); % % retrieve the triaxial radii of Earth. % radii = cspice_bodvrd( 'EARTH', 'RADII', 3 ); % % Normalize the position to factors of the radii. % pos = [ pos(1)/radii(1)^2, pos(2)/radii(2)^2, pos(3)/radii(3)^2 ]; % % Create the SPICE plane. % plane = cspice_nvc2pl( pos, 1. ); % % Calculate the intercept. % [term, found] = ## ParticularsAn ellipsoid and a plane can intersect in an ellipse, a single point, or the empty set. ## Required ReadingFor important details concerning this module's function, please refer to the CSPICE routine inedpl_c. MICE.REQ ELLIPSES.REQ PLANES.REQ ## Version-Mice Version 1.0.1, 11-JUN-2013, EDW (JPL) I/O descriptions edits to conform to Mice documentation format. -Mice Version 1.0.0, 27-AUG-2012, EDW (JPL) ## Index_Entriesintersection of ellipsoid and plane |

Wed Apr 5 18:00:33 2017