cspice_vdist

 Abstract I/O Examples Particulars Required Reading Version Index_Entries
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#### Abstract

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CSPICE_VDIST returns the scalar distance between two three-dimensional
vectors.

For important details concerning this module's function, please refer to
the CSPICE routine vdist_c.

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#### I/O

```
Given:

vec1,
vec2    two arbitrary double precision 3-vectors, the distance between
which is desired.

the call:

dist = cspice_vdistg( vec1, vec2 )

returns:

dist   double precision scalar distance between 'vec1' and 'vec2'.
This is defined as

||  v1 - v2  ||,

where || x || indicates the Euclidean norm of the vector x.

```

#### Examples

```
Any numerical results shown for this example may differ between
platforms as the results depend on the SPICE kernels used as input
and the machine specific arithmetic implementation.

v1 = [ 12.3d   , -4.32d ,  76.d  ]
v2 = [ 23.0423d, -11.99d, -0.10d ]

print, cspice_vdist( v1, v2)

IDL outputs:

77.236234

Native IDL code to calculate the same scalar result:

norm( v1 - v2 )

The IDL function accepts an arbitrary size N-vectors.

```

#### Particulars

```
The Euclidean norm of a three-dimensional 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[0], a[1], a[2] )    and    ( b[0], b[1], b[2] ),

then the distance between A and B is the norm of the difference
A - B, which has components

(  a[0] - b[0],  a[1] - b[1],  a[2] - b[2]  ).

A related routine is cspice_vdistg, which computes the distance between
two vectors of general dimension.

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ICY.REQ

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#### Version

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-Icy Version 1.0.2, 13-JUN-2011, EDW (JPL)

Edits to comply with NAIF standard for Icy headers.

Corrected version ID for 18-APR-2006 entry "1.0.1"
rather than "1.0.2."

-Icy Version 1.0.1, 18-APR-2006, EDW (JPL)

-Icy Version 1.0.0, 16-JUN-2003, EDW (JPL)

```

#### Index_Entries

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distance between 3-dimensional vectors

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`Wed Apr  5 17:58:04 2017`