> Sorry, I missed the post where you clarified that you weren't just > looking for factor pairs. There's got to be a way to extend this idea > to make it more arbitrary, but I haven't figured it out yet. At least > we know there's going to be an upper bound on the number of elements you > have in a factor list (the sum of the exponents of the prime factors). > > What if my approach were extended to recursively fill out some sort of > tree structure? If you took the list of factor pairs and then made the > function search for each of the left or right factor's binary pairs then > you'd be building the list for size=3. Unless we did something tricky > here, we'd get back a bunch of duplicate entries and it would only get > worse as we descend deeper into the tree. I'll see if I can come up > with the 'trick'.
That is essentially what I have been playing with. I begin by computing the factor pairs, and then recursively compute the factor pairs of the left and right factors of each pair. I don't have the recursion working properly yet, but I think that is a good approach. And yes, it does sound like this ends up being a factor tree or sorts. But not exactly, I just sketched the tree and it is more like the set of all possible factor trees. Brian > -Jake > > > -Jake > > > >> On 23/01/2008, Brian Granger <[EMAIL PROTECTED]> wrote: > >> > >> > >>> Hi, > >>> > >>> I am working on a parallel/distributed array library for > >>> python/ipython. For this library I need to be able to compute the > >>> multiplicative partitions of positive integers: > >>> > >>> 12 => (2,6), (3,4) > >>> > >>> A few questions about this: > >>> > >>> 1) Is there a good algorithm for computing these. I can think of > >>> silly ways of doing it, but I imagine there are more efficient ways. > >>> > >>> 2) Does anyone know of a implementation of such an algorithms (python, c, > >>> etc.) > >>> > >>> 3) Does anyone know of a BSD license compatible (please don't shoot me > >>> :) ) implementation. Because these distributed arrays are being > >>> developed as a part of ipython, it needs to be BSD. > >>> > >>> Thanks! > >>> > >>> Brian > >>> > >>> > >>> > >> > >> > > > > > > > > > > > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
