I don't care about the number of files, only the total size per partition. What Pascal suggested was my initial idea - it's probably good enough. Another ideas is to generate a lot of random partitions and pick the best one but I think Raul points up what's missing from the problem statement: a measure of how good a solution is.
I don't see how this is like ensuring that fractional portions sum to 100%. My idea is more to divide up files I want to back up onto a medium with a specific capacity, like a writeable DVD, assuming the sum total is such that an even number of discs should suffice. Anyway, I'll try a couple of these ideas and see how they work. Thanks for everyone's input. On Fri, May 20, 2016 at 10:27 PM, Don Guinn <dongu...@gmail.com> wrote: > Sounds like making sure that percentages add to 100%. Why people check that > is curious. > On May 20, 2016 1:11 PM, "'Pascal Jasmin' via Programming" < > programm...@jsoftware.com> wrote: > > > Do you want an almost equal number of files in each group as well? > > > > A quick approach is to randomly split the files into groups, then > > repeatedly take a large file out of a too big group, and place it into a > > too small group. The average/target group size is quickly calculated. > > > > Also take a small file out of a too long group, and place it into a too > > short group. > > > > > > > > > > ----- Original Message ----- > > From: Devon McCormick <devon...@gmail.com> > > To: J-programming forum <programm...@jsoftware.com> > > Sent: Friday, May 20, 2016 1:37 PM > > Subject: Re: [Jprogramming] Even partitions > > > > It's an arbitrary grouping so that the sum of file sizes in each group is > > nearly equal between groups. To roughly approximate a distribution, you > > could use something like this: > > szs=. (+/16 4000?@$400) + (+/8 4000?@$2e3) + (+/4 4000?@$5e5) + > 4000?@$1e6 > > On May 20, 2016 10:48 AM, "David Porter" <dpor...@cissoid.net> wrote: > > > > > Groups based on what? > > > > > > Dave > > > On 5/20/2016 10:11 AM, Devon McCormick wrote: > > > > > >> I have a few thousand photos I want to put into a small number of > groups > > >> as > > >> equally-sized as possible. It looks like a knapsack problem but I > only > > >> need to get within some tolerant equality. > > >> > > >> Has anyone done something like this? > > >> > > >> Thanks, > > >> > > >> Devon > > >> ---------------------------------------------------------------------- > > >> For information about J forums see > http://www.jsoftware.com/forums.htm > > > > >> > > > > > > ---------------------------------------------------------------------- > > > For information about J forums see http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- Devon McCormick, CFA Quantitative Consultant ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
