Find the closest vector in a list to a given vector v

distances.hs

type Vector3D = (Float, Float, Float)

arr :: [ Vector3D ]
arr = [ ( 35, 30, 39 ),( 20, 12,  5 ) ]

tp :: Vector3D
tp = (19,13,3)


dist:: Vector3D -> Vector3D -> Float
dist (x1, y1, z1) (x2, y2, z2 ) = abs(x1-x2) + abs(y1-y2) + abs(z1-z2)

euclidDist:: Vector3D -> Vector3D -> Float
euclidDist (x1, y1, z1) (x2, y2, z2 ) = sqrt( (x1-x2)^2 + (y1-y2)^2 + (z1-z2)^2 )


proximities:: [Vector3D] -> Vector3D -> (Vector3D->Vector3D->Float) -> [ Float ]
proximities l v d = map (d v) l


array_proximity:: [Vector3D] -> Vector3D -> (Vector3D->Vector3D->Float) -> (Float, Int)
array_proximity l v d = minimum (zip (proximities l v d) [0..])

-- *Main> array_proximity arr tp dist
-- (4.0,1)
-- *Main> array_proximity arr tp euclidDist
-- (2.4494898,1)