What does nearest neighbor to a point mean in the docs?

[ogencoglu]

# Find the nearest neighbors in the RTree to the point (5, 5)
results = rt.neighbors(tree, 5, 5)

What is the definition of nearest (or distance in general) between bounding boxes (rectangles) and a point here?

[kylebarron]

It's the distance to the closest point of the box. If the point is inside the box, it has a distance of 0; otherwise some point on the exterior of the box is used.

This is the function used to find the nearest corner or edge of the box:

geo-index/src/rtree/trait.rs

Lines 295 to 306 in 9ca258b

	/// 1D distance from a value to a range.
	#[allow(dead_code)]
	#[inline]
	fn axis_dist<N: IndexableNum>(k: N, min: N, max: N) -> N {
	if k < min {
	min - k
	} else if k <= max {
	N::zero()
	} else {
	k - max
	}
	}

(I'm not sure the ordering for nearest boxes when multiple have a distance of 0, maybe it's undefined)

[ogencoglu]

Thanks for the swift reply.

[kylebarron]

We can keep this open to add this explanation to the docs.