Non-rotationally symmetric surfaces are produced by the ability to servo a tool in a coordinated manner, with a workpiece rotating on a two-axis lathe. The diamond machining of far off-axis segments ...

From Simons Science News (find original story here). Mathematicians classify objects by their symmetries. If you turn a five-armed starfish a fifth of a revolution, it looks unchanged, so it has a ...

Journal of the Royal Statistical Society. Series C (Applied Statistics) When sample units are plotted against orthogonal principal axes in a components analysis, the concept of (Euclidean) distance ...