Re: NearestFunction Algorithm

*To*: mathgroup at smc.vnet.net*Subject*: [mg85589] Re: NearestFunction Algorithm*From*: "D. Grady" <D.C.Grady at gmail.com>*Date*: Thu, 14 Feb 2008 06:25:11 -0500 (EST)*References*: <foue29$m1v$1@smc.vnet.net>

On Feb 13, 3:42=A0am, "jwmerr... at gmail.com" <jwmerr... at gmail.com> wrote: > I'm looking to iteratively assign a list of initial points to a list > of final points such that at each step, the initial point that is > furthest from its nearest final point is assigned to its nearest final > point. =A0That final points is then no longer available to other initial > points. > > I noticed that you can speed up repeated uses of Nearest by calling it > with only one argument in order to produce a NearestFunction, and then > using that in later calculations. =A0Can anyone give me a clue about how > this actually works? > > Is it possible to manipulate a NearestFunction in order to remove > points that have already been assigned? > > Regards, > > Jason Merrill If you have a list of points, pts = {1,2,3,4,5} then you could make a NearestFunction by writing myFunction = Nearest[pts] myFunction works just like any other function, so if you want to find the nearest element to 7, you write myFunction[7] As far as removing points that have already been assigned, I don't think you can do that without creating a new NearestFunction at every step of the algorithm. -Daniel