| vequg_c |
|
Table of contents
Procedure
vequg_c ( Vector equality, general dimension )
void vequg_c ( ConstSpiceDouble * vin,
SpiceInt ndim,
SpiceDouble * vout )
AbstractMake one double precision vector of arbitrary dimension equal to another. Required_ReadingNone. KeywordsASSIGNMENT VECTOR Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
vin I Double precision n-dimensional vector.
ndim I Dimension of `vin' (and also `vout').
vout O Double precision n-dimensional vector set equal
to `vin'.
Detailed_Inputvin is an arbitrary, double precision n-dimensional vector. ndim is the dimension of `vin' and `vout'. Detailed_Output
vout is a double precision n-dimensional vector set equal
to `vin'.
ParametersNone. ExceptionsError free. FilesNone. ParticularsThe code simply sets each component of `vout' equal to the corresponding component of `vin'. Note that this routine may be used in place of moved_c, which sets each output array element equal to the corresponding input array element. Examples
The 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) Lets assume we have a pointing record that contains the
start time of an interpolation interval, the components of
the quaternion that represents the C-matrix associated with
the start time of the interval, and the angular velocity vector
of the interval. The following example demonstrates how to
extract the time, the quaternion and the angular velocity
vector into separate variables for their processing.
Example code begins here.
/.
Program vequg_ex1
./
#include <stdio.h>
#include "SpiceUsr.h"
int main( )
{
/.
Local variables.
./
SpiceDouble av [3];
SpiceDouble quat [4];
SpiceDouble time;
/.
Define the pointing record. We would normally obtain it
from, e.g. CK readers or other non SPICE data files.
./
SpiceDouble record [8] = { 283480.753, 0.99999622,
0.0, 0.0,
-0.0027499965, 0.0,
0.0, 0.01 };
/.
Get the time, quaternion and angular velocity vector
into separate variables.
./
time = record[0];
vequg_c ( record+1, 4, quat );
vequ_c ( record+5, av );
/.
Display the contents of the variables.
./
printf( "Time : %10.3f\n", time );
printf( "Quaternion :\n" );
printf( "%15.10f %14.10f %14.10f %14.10f\n",
quat[0], quat[1], quat[2], quat[3] );
printf( "Angular velocity:\n" );
printf( "%15.10f %14.10f %14.10f\n", av[0], av[1], av[2] );
return ( 0 );
}
When this program was executed on a Mac/Intel/cc/64-bit
platform, the output was:
Time : 283480.753
Quaternion :
0.9999962200 0.0000000000 0.0000000000 -0.0027499965
Angular velocity:
0.0000000000 0.0000000000 0.0100000000
RestrictionsNone. 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 1.1.0, 23-JUL-2020 (JDR)
Edited the header to comply with NAIF standard. Added complete
code example based on existing example.
Removed check for "ndim" being positive in order to replicate
behaviour of SPICELIB equivalent routine.
-CSPICE Version 1.0.0, 23-AUG-1999 (EDW) (NJB) (WMO)
Index_Entriesassign an n-dimensional vector to another Link to routine vequg_c source file vequg_c.c |
Fri Dec 31 18:41:14 2021