I made a mistake in the reference. EDIT: this reference was wrong the original post --- by M. C. Er, The Computer Journal, Vol. 31, 1988, 283-284, CORRECTION: the reference for the Haskell source should read +++ by Brent Yorgey and Conrad Parker,The Monad.Reader Issue 8 , September 10, 2007
Sorry about that - I had read several papers on the subject some time ago and forgot which one I implemented. I will open a trac ticket with this ASAP. Thanks for the advice, Denis On Thursday, February 13, 2020 at 6:08:33 PM UTC+1, Denis wrote: > > This is a re-post from sage-combinat-devel with the same subject. Please > post answers there. > > I have translated the Haskell code for vector partitions by M. C. Er, The > Computer Journal, Vol. 31, 1988, 283-284, into Python (2 or 3, stand-alone > file with 60 lines total). > > The code works significantly faster than the Sage implementation: > > ┌────────────────────────────────────────────────────────────────────┐ > │ SageMath version 9.0, Release Date: 2020-01-01 │ > │ Using Python 3.7.3. Type "help()" for help. │ > └────────────────────────────────────────────────────────────────────┘ > sage: import vpartitions > sage: %time myvparts=vpartitions.vPartitionso([6,6,6]) > CPU times: user 9.13 s, sys: 89.8 ms, total: 9.22 s > Wall time: 9.22 s > sage: %time sagevparts=list(VectorPartitions([6,6,6])) > CPU times: user 2min 10s, sys: 177 ms, total: 2min 10s > Wall time: 2min 10s > sage: myvparts[::-1]==sagevparts > True > > If someone would take over the job of contributing this code to Sage, I > would be glad to help. There are a few caveats: > > 1) the code is recursive; > 2) there is no "min" option like in the Sage implementation. > > I do not know how difficult (or necessary) it would be to address these > points. > > Of course, anyone can take it up straight from Er's paper instead, I won't > be jealous:) > > Cheers, > > Denis > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/398b54b4-cd62-40d4-897a-7400d8fd08ad%40googlegroups.com.
