1. A system for evaluating a one-to-one mapping between a first spatial point set and a second spatial point set in nD, the system comprising: (a) a programmable processor; and (b) a memory coupled with the programmable processor and embodying information indicative of instructions that cause the programmable processor to perform operations comprising: receiving a first and a second spatial point sets in nD and a one-to-one mapping between the two spatial point sets; generating a pair of mapped agreeable (n+1)-combinations in the first point set; computing two affine transformations that transform said pair of mapped agreeable (n+1)-combinations to correspondents in the second point set; computing the difference of the left sub-matrices of said two affine transformations; computing a local distance measure based on said difference.