SpiceDouble vdist_c ( ConstSpiceDouble v1[3],
ConstSpiceDouble v2[3] )
Return the distance between two threedimensional vectors.
None.
VECTOR
Variable I/O Description
  
v1,
v2 I Two 3vectors.
The function returns the distance between v1 and v2.
v1,
v2 are two vectors in threedimensional space, the
distance between which is desired.
The function returns the distance between v1 and v2. This is
defined as
 v1  v2 ,
where  x  indicates the Euclidean norm of the vector x.
None.
Error free.
None.
This function is simply shorthand for the code
vsub_c ( v1, v2, diff );
dist = vnorm_c ( diff );
Using this function saves you the annoyance of declaring local
storage for the difference vector diff.
The Euclidean norm of a threedimensional vector (x, y, z) is
defined as
1/2
2 2 2
( x + y + z ).
This number is the distance of the point (x, y, z) from the
origin. If A and B are two vectors whose components are
( A(1), A(2), A(3) ) and ( B(1), B(2), B(3) ),
then the distance between A and B is the norm of the difference
A  B, which has components
( A(1)  B(1), A(2)  B(2), A(3)  B(3) ).
A related routine is vdistg_, which computes the distance between
two vectors of general dimension.
1) If v1 is
( 2.0, 3.0, 0. )
and v2 is
( 5.0, 7.0, 12. ),
vdist_c (v1, v2) will be 13..
2) If VGR2 and NEP are states of the Voyager 2 spacecraft and
Neptune with respect to some common center at a given time
ET, then
vdist_c ( VGR2, NEP )
yields the distance between the spacecraft and Neptune at time
ET.
None.
None.
N.J. Bachman (JPL)
CSPICE Version 1.2.0, 22OCT1998 (NJB)
Made input vectors const. Removed #include of SpiceZfc.h.
CSPICE Version 1.1.0, 06MAR1998 (EDW)
Removed non printing character.
CSPICE Version 1.0.0, 08FEB1998 (EDW)
distance between 3dimensional vectors
