An equidistant line is a line that at any given point is the same distance to
the points that defines it. In 2 dimensions it is equivalent to the bisector
of the two points. In 3 dimensions it is defined for 3 points (2 points would
give a bisector plane).

`equidistant_line(x, y, z = NULL)`

## Arguments

- x, y, z
Vector of points. If z is given they must be in 3D, otherwise in
2D

## Examples

```
equidistant_line(
point(3, 7, 2),
point(6, -4, 9),
point(2, 1, -5)
)
#> <3D lines [1]>
#> [1] <x:3.98, y:-0.679, z:2.3, dx:119, dy:14, dz:-29>
# In 2D you get the bisector
equidistant_line(point(2, 5), point(3, 2)) == bisector(point(2, 5), point(3, 2))
#> [1] TRUE
```