z_coord (_, _, z) = z
instance Num Point where
- p1 + p2 = (x1+x2, y1+y2, z1+z2)
- where
- x1 = x_coord p1
- x2 = x_coord p2
- y1 = y_coord p1
- y2 = y_coord p2
- z1 = z_coord p1
- z2 = z_coord p2
-
- p1 - p2 = (x1-x2, y1-y2, z1-z2)
- where
- x1 = x_coord p1
- x2 = x_coord p2
- y1 = y_coord p1
- y2 = y_coord p2
- z1 = z_coord p1
- z2 = z_coord p2
-
- p1 * p2 = (x1*x2, y1*y2, z1*z2)
- where
- x1 = x_coord p1
- x2 = x_coord p2
- y1 = y_coord p1
- y2 = y_coord p2
- z1 = z_coord p1
- z2 = z_coord p2
-
+ (x1,y1,z1) + (x2,y2,z2) = (x1+x2, y1+y2, z1+z2)
+ (x1,y1,z1) - (x2,y2,z2) = (x1-x2, y1-y2, z1-z2)
+ (x1,y1,z1) * (x2,y2,z2) = (x1*x2, y1*y2, z1*z2)
abs (x, y, z) = (abs x, abs y, abs z)
signum (x, y, z) = (signum x, signum y, signum z)
fromInteger n = (fromInteger n, fromInteger n, fromInteger n)
z2 = z_coord p2
--- | Returns 'True' if p1 'is_close' to p2, 'False' otherwise.
+-- | Returns 'True' if p1 is close to (within 'epsilon' of) p2,
+-- 'False' otherwise.
is_close :: Point -> Point -> Bool
is_close p1 p2 = (distance p1 p2) ~= 0