vsub_c |

Table of contents## Procedurevsub_c ( Vector subtraction, 3 dimensions ) void vsub_c ( ConstSpiceDouble v1[3], ConstSpiceDouble v2[3], SpiceDouble vout[3] ) ## AbstractCompute the difference between two double precision 3-dimensional vectors. ## Required_ReadingNone. ## KeywordsVECTOR ## Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- v1 I First vector (minuend). v2 I Second vector (subtrahend). vout O Difference vector, v1 - v2. ## Detailed_Inputv1 is a double precision 3-dimensional vector which is the minuend (i.e. first or left-hand member) in the vector subtraction. v2 is a double precision 3-dimensional vector which is the subtrahend (i.e. second or right-hand member) in the vector subtraction. ## Detailed_Outputvout is a double precision 3-dimensional vector which represents the vector difference, v1 - v2. `vout' may overwrite either `v1' or `v2'. ## ParametersNone. ## ExceptionsError free. ## FilesNone. ## ParticularsFor each value of the index `i' from 0 to 2, this routine performs the following subtraction: vout[i] = v1[i] - v2[i] No error checking is performed to guard against numeric overflow or underflow. ## ExamplesThe numerical results shown for this example may differ across platforms. The results depend on the SPICE kernels used as input, the compiler and supporting libraries, and the machine specific arithmetic implementation. 1) Define two sets of 3-dimensional vectors and compute the difference from each vector in first set with the corresponding vector in the second set. Example code begins here. /. Program vsub_ex1 ./ #include <stdio.h> #include "SpiceUsr.h" int main( ) { /. Local parameters. ./ #define SETSIZ 3 /. Local variables. ./ SpiceDouble vout [3]; SpiceInt i; /. Define the two vector sets. ./ SpiceDouble v1 [SETSIZ][3] = { {1.0, 2.0, 3.0}, {1.0, 2.0, 3.0}, {1.0, 2.0, 3.0} }; SpiceDouble v2 [SETSIZ][3] = { { 1.0, 1.0, 1.0}, {-1.0, -2.0, -3.0}, {-1.0, 2.0, -3.0} }; /. Calculate the difference between each pair of vectors ./ for ( i = 0; i < SETSIZ; i++ ) { ## Restrictions1) The user is required to determine that the magnitude each component of the vectors is within the appropriate range so as not to cause floating point overflow. No error recovery or reporting scheme is incorporated in this routine. ## Literature_ReferencesNone. ## Author_and_InstitutionN.J. Bachman (JPL) J. Diaz del Rio (ODC Space) W.M. Owen (JPL) E.D. Wright (JPL) ## Version-CSPICE Version 1.1.2, 05-JUL-2021 (JDR) Edited the header to comply with NAIF standard. Added complete code example based on existing example. -CSPICE Version 1.1.1, 07-NOV-2003 (EDW) Corrected a mistake in the second example's value for VOUT, i.e. replaced [1D24, 2D23, 0.0] with [-1e24, 0.0, 0.0]. -CSPICE Version 1.1.0, 22-OCT-1998 (NJB) Made input vectors const. -CSPICE Version 1.0.0, 08-FEB-1998 (EDW) (WMO) ## Index_Entries3-dimensional vector subtraction |

Fri Dec 31 18:41:15 2021