vsubg_c |

Table of contents## Procedurevsubg_c ( Vector subtraction, general dimension ) void vsubg_c ( ConstSpiceDouble * v1, ConstSpiceDouble * v2, SpiceInt ndim, SpiceDouble * vout ) ## AbstractCompute the difference between two double precision vectors of arbitrary dimension. ## Required_ReadingNone. ## KeywordsVECTOR ## Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- v1 I First vector (minuend). v2 I Second vector (subtrahend). ndim I Dimension of `v1', `v2', and `vout'. vout O Difference vector, v1 - v2. ## Detailed_Inputv1 is a double precision vector of arbitrary dimension which is the minuend (i.e. first or left-hand member) in the vector subtraction. v2 is a double precision vector of arbitrary dimension which is the subtrahend (i.e. second or right-hand member) in the vector subtraction. ndim is the dimension of `v1' and `v2' (and `vout'). ## Detailed_Outputvout is a double precision n-dimensional vector which represents the vector difference, v1 - v2. `vout' may overwrite `v1' or `v2'. ## ParametersNone. ## ExceptionsError free. ## FilesNone. ## ParticularsFor each value of the index `i' from 0 to ndim-1, this function performs the following subtraction: vout[i] = v1[i] - v2[i] No error checking is performed to guard against numeric overflow or underflow. `vout' may overwrite `v1' or `v2'. ## 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 n-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 vsubg_ex1 ./ #include <stdio.h> #include "SpiceUsr.h" int main( ) { /. Local parameters. ./ #define NDIM 4 #define SETSIZ 3 /. Local variables. ./ SpiceDouble vout [NDIM]; SpiceInt i; /. Define the two vector sets. ./ SpiceDouble v1 [SETSIZ][NDIM] = { {1.0, 2.0, 3.0, 4.0}, {1.0, 2.0, 3.0, 4.0}, {1.0, 2.0, 3.0, 4.0} }; SpiceDouble v2 [SETSIZ][NDIM] = { { 1.0, 1.0, 1.0, 1.0}, {-1.0, -2.0, -3.0, -4.0}, {-1.0, 2.0, -3.0, 4.0} }; /. Calculate the difference between each pair of vectors ./ for ( i = 0; i < SETSIZ; i++ ) { ## Restrictions1) No error checking is performed to guard against numeric overflow. The programmer is thus required to insure that the values in `v1' and `v2' are reasonable and will not cause overflow. No error recovery or reporting scheme is incorporated in this routine. 2) It is assumed the proper amount of memory has been allocated for `v1', `v2' and `vout'. ## 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 1.1.1, 05-JUL-2021 (JDR) Edited the header to comply with NAIF standard. Added complete code example based on existing example. -CSPICE Version 1.1.0, 22-OCT-1998 (NJB) Made input vectors const. -CSPICE Version 1.0.0, 05-MAR-1998 (EDW) (WMO) ## Index_Entriesn-dimensional vector subtraction |

Fri Dec 31 18:41:15 2021