vlcomg_c

Index Page vlcomg_c
A B C D E F G H I J K L M N O P Q R S T U V W X
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
       void vlcomg_c ( SpiceInt            n,
                       SpiceDouble         a,
                       ConstSpiceDouble *  v1,
                       SpiceDouble         b,
                       ConstSpiceDouble *  v2,
                       SpiceDouble      *  sum )
#### Abstract
       Compute a vector linear combination of two double precision
       vectors of arbitrary dimension.
#### Required_Reading
       None.
#### Keywords
       VECTOR
#### Brief_I/O
        VARIABLE  I/O  DESCRIPTION
        --------  ---  --------------------------------------------------
        n          I   Dimension of vector space
        a          I   Coefficient of v1
        v1         I   Vector in n-space
        b          I   Coefficient of v2
        v2         I   Vector in n-space
        sum        O   Linear Vector Combination a*v1 + b*v2
#### Detailed_Input
        n   This variable contains the dimension of the v1, v2 and sum.
        a   This double precision variable multiplies v1.
        v1  This is an arbitrary, double precision n-dimensional vector.
        b   This double precision variable multiplies v2.
        v2  This is an arbitrary, double precision n-dimensional vector.
#### Detailed_Output
        sum   is an arbitrary, double precision n-dimensional vector
              which contains the linear combination a*v1 + b*v2.
#### Parameters
        None.
#### Exceptions
       Error free.
#### Files
        None
#### Particulars
        For each index from 1 to n, this routine implements in C
        code the expression:

        sum[i] = a*v1[i] + b*v2[i]

        No error checking is performed to guard against numeric overflow.
#### Examples
        We can easily use this routine to perform vector projections
        to 2-planes in n-space.  Let x be an arbitray n-vector
        and let u and v be orthonormal n-vectors spanning the plane
        of interest.  The projection of x onto this 2-plane, projuv can
        be obtained by the following code fragment.

           vlcomg_c ( n, vdot_c(x,u,n), u, vdot_c(x,v,n), v, projuv );
#### Restrictions
        No error checking is performed to guard against numeric overflow
        or underflow.  The user is responsible for insuring that the
        input values are reasonable.
#### Literature_References
        None
#### Author_and_Institution
        W.L. Taber      (JPL)
#### Version
       -CSPICE Version 1.0.0, 30-JUN-1999
#### Index_Entries
       linear combination of two n-dimensional vectors
#### Link to routine vlcomg_c source file vlcomg_c.c

    Thu Apr 16 08:59:32 2009