wndifd_c |

Table of contents## Procedurewndifd_c ( Difference two DP windows ) void wndifd_c ( SpiceCell * a, SpiceCell * b, SpiceCell * c ) ## AbstractPlace the difference of two double precision windows into a third window. ## Required_ReadingWINDOWS ## KeywordsWINDOWS ## Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- a, b I Input windows. c O Difference of `a' and `b'. ## Detailed_Inputa, b are SPICE windows, each of which contains zero or more intervals. `a' and `b' must be declared as double precision SpiceCells. CSPICE provides the following macros, which declare and initialize the cells SPICEDOUBLE_CELL ( a, ASZ ); SPICEDOUBLE_CELL ( b, BSZ ); where ASZ and BSZ are the maximum capacity of `a' and `b', respectively. ## Detailed_Outputc is the output SPICE window, containing the difference of `a' and `b' --- every point contained in `a', but not contained in `b'. `c' must be distinct from both `a' and `b'. `c' must be declared as a double precision SpiceCell. CSPICE provides the following macro, which declares and initializes the cell SPICEDOUBLE_CELL ( c, CSZ ); where CSZ is the maximum capacity of `c'. ## ParametersNone. ## Exceptions1) If the difference of the two windows results in an excess of elements, the error SPICE(WINDOWEXCESS) is signaled by a routine in the call tree of this routine. 2) The cardinality of the input windows must be even. Left endpoints of stored intervals must be strictly greater than preceding right endpoints. Right endpoints must be greater than or equal to corresponding left endpoints. Invalid window data are not diagnosed by this routine and may lead to unpredictable results. 3) If any the `a', `b' or `c' cell arguments has a type other than SpiceDouble, the error SPICE(TYPEMISMATCH) is signaled. ## FilesNone. ## ParticularsMathematically, the difference of two windows contains every point contained in the first window but not contained in the second window. C offers no satisfactory floating point representation of open intervals. Thus, for floating point windows we must return the closure of the set theoretical difference: that is, the difference plus the endpoints of the first window that are contained in the second window. ## ExamplesLet a contain the intervals [ 1, 3 ] [ 7, 11 ] [ 23, 27 ] and b contain the intervals [ 2, 4 ] [ 8, 10 ] [ 16, 18 ] Then the difference of a and b contains the intervals [ 1, 2 ] [ 7, 8 ] [ 10, 11 ] [ 23, 27 ] ## RestrictionsNone. ## Literature_ReferencesNone. ## Author_and_InstitutionN.J. Bachman (JPL) J. Diaz del Rio (ODC Space) H.A. Neilan (JPL) B.V. Semenov (JPL) W.L. Taber (JPL) I.M. Underwood (JPL) ## Version-CSPICE Version 1.0.2, 24-AUG-2021 (JDR) Edited the header to comply with NAIF standard. Added entry #3 in -Exceptions section. Extended description of arguments "a", "b" and "c" to include type and preferred declaration method. Improved -Particulars section. -CSPICE Version 1.0.1, 11-FEB-2013 (BVS) Corrected typo in Brief I/O section. -CSPICE Version 1.0.0, 29-JUL-2002 (NJB) (HAN) (WLT) (IMU) ## Index_Entriesdifference two d.p. windows |

Fri Dec 31 18:41:15 2021