vdotg_c |

Table of contents## Procedurevdotg_c ( Vector dot product, general dimension ) SpiceDouble vdotg_c ( ConstSpiceDouble * v1, ConstSpiceDouble * v2, SpiceInt ndim ) ## AbstractCompute the dot product of two vectors of arbitrary dimension. ## Required_ReadingNone. ## KeywordsVECTOR ## Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- v1 I First vector in the dot product. v2 I Second vector in the dot product. ndim I Dimension of `v1' and `v2'. The function returns the value of the dot product of `v1' and `v2'. ## Detailed_Inputv1, v2 are two arbitrary double precision n-dimensional vectors. ndim is the dimension of `v1' and `v2'. ## Detailed_OutputThe function returns the value of the dot product (inner product) of `v1' and `v2': < v1, v2 > ## ParametersNone. ## ExceptionsError free. ## FilesNone. ## Particulars
## 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) Suppose that you have a set of double precision n-dimensional vectors. Check if they are orthogonal to the Z-axis in n-dimensional space. Example code begins here. /. Program vdotg_ex1 ./ #include <stdio.h> #include "SpiceUsr.h" int main( ) { /. Local parameters. ./ #define NDIM 4 #define SETSIZ 5 /. Local variables. ./ SpiceInt i; /. Define the vector set. ./ SpiceDouble v1 [SETSIZ][NDIM] = { { 1.0, 0.0, 0.0, 0.0 }, { 0.0, 1.0, 0.0, 3.0 }, { 0.0, 0.0, -6.0, 0.0 }, {10.0, 0.0, -1.0, 0.0 }, { 0.0, 0.0, 0.0, 1.0 } }; SpiceDouble z [NDIM] = { 0.0, 0.0, 1.0, 0.0 }; /. Check the orthogonality with respect to `z' of each vector in `v1'. ./ for ( i = 0; i < SETSIZ; i++ ) { printf( "\n" ); printf( "Input vector (V1): %5.1f %5.1f %5.1f %5.1f\n", v1[i][0], v1[i][1], v1[i][2], v1[i][3] ); if ( ## Restrictions1) The user is responsible for determining that the vectors `v1' and `v2' are not so large as to cause numeric overflow. In most cases this will not present a problem. ## 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 1.2.0, 13-AUG-2021 (JDR) Edited the header to comply with NAIF standard. Added complete code example. Improved -Particulars section. Removed check for "ndim" being positive in order to replicate behavior of SPICELIB equivalent routine. -CSPICE Version 1.1.0, 22-OCT-1998 (NJB) Made input vectors const. Converted check-in style to discovery. -CSPICE Version 1.0.0, 31-MAR-1998 (EDW) (WMO) ## Index_Entriesdot product of n-dimensional vectors |

Fri Dec 31 18:41:14 2021