Index of Functions: A B C D E F G H I J K L M N O P Q R S T U V W X
Index Page vscl_c

Table of contents

Procedure Abstract Required_Reading Keywords Brief_I/O Detailed_Input | Detailed_Output Parameters Exceptions Files Particulars Examples | Restrictions Literature_References Author_and_Institution Version Index_Entries

#### Procedure

       vscl_c ( Vector scaling, 3 dimensions )

       void vscl_c ( SpiceDouble        s,
                     ConstSpiceDouble   v1[3],
                     SpiceDouble        vout[3] )

#### Abstract

       Multiply a scalar and a double precision 3-dimensional vector.

#### Required_Reading

       None.

#### Keywords

       VECTOR

#### Brief_I/O

       VARIABLE  I/O  DESCRIPTION
       --------  ---  --------------------------------------------------
       s          I   Scalar to multiply a vector.
       v1         I   Vector to be multiplied.
       vout       O   Product vector, s * v1.

#### Detailed_Input

       s           is a double precision scalar used to multiply the vector
                   `v1'.

       v1          is a double precision 3-dimensional vector, which is to
                   be scaled by `s'.

#### Detailed_Output

       vout        is a double precision 3-dimensional vector containing
                   the product of the scalar with the vector `v1'. `vout' may
                   overwrite `v1'.

#### Parameters

       None.

#### Exceptions

       Error free.

#### Files

       None.

#### Particulars

       For each value of the index `i' from 0 to 2, this function
       performs the following multiplication

          vout[i] = s * v1[i];

       No error checking is performed to guard against numeric overflow
       or underflow.

#### 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) Define a sets of scalar double precision values and use them
          to scale a given 3-dimensional vector.

          Example code begins here.

          /.
             Program vscl_ex1
          ./
          #include <stdio.h>
          #include "SpiceUsr.h"

          int main( )
          {

             /.
             Local parameters.
             ./
             #define SETSIZ       3

             /.
             Local variables.
             ./
             SpiceDouble          vout   [3];

             SpiceInt             i;

             /.
             Define the set of scalars and the input vector.
             ./
             SpiceDouble          s      [SETSIZ] = { 3.0, 0.0, -1.0 };

             SpiceDouble          v1     [3]      = { 1.0, 2.0, -3.0 };

             printf( "Input vector :  %5.1f %5.1f %5.1f\n",
                                       v1[0], v1[1], v1[2] );
             printf( "\n" );

             /.
             Calculate product of each scalar and `v1'.
             ./
             for ( i = 0; i < SETSIZ; i++ )
             {

                vscl_c ( s[i], v1, vout );

                printf( "Scale factor :  %5.1f\n", s[i] );
                printf( "Output vector:  %5.1f %5.1f %5.1f\n",
                                  vout[0], vout[1], vout[2] );
                printf( "\n" );

             }

             return ( 0 );
          }

          When this program was executed on a Mac/Intel/cc/64-bit
          platform, the output was:

          Input vector :    1.0   2.0  -3.0

          Scale factor :    3.0
          Output vector:    3.0   6.0  -9.0

          Scale factor :    0.0
          Output vector:    0.0   0.0  -0.0

          Scale factor :   -1.0
          Output vector:   -1.0  -2.0   3.0

#### Restrictions

       1)  The user is responsible for insuring that no floating point
           overflow occurs from multiplying `s' by any component of `v1'. No
           error recovery or reporting scheme is incorporated in this
           function.

#### Literature_References

       None.

#### Author_and_Institution

       N.J. Bachman        (JPL)
       J. Diaz del Rio     (ODC Space)
       W.M. Owen           (JPL)
       E.D. Wright         (JPL)

#### Version

       -CSPICE Version 1.1.1, 23-JUL-2020 (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 vector const.

       -CSPICE Version 1.0.0, 08-FEB-1998 (EDW) (WMO)

#### Index_Entries

       3-dimensional vector scaling

#### Link to routine vscl_c source file vscl_c.c

    Fri Dec 31 18:41:15 2021