I think that as more people use Sage -- especially to do highly nontrivial computations like this, which are likely unavailable in other systems -- we will get more cases like this. So, to be realistic, there should perhaps be two stages to the "publication" of such things:
(1) the .sage file (or files) are distributed by the author, ready to be attached by users; (2) a spkg is made for incorporation into Sage long-term. For (1) we have (as far as I know) no mechanism yet for maintaining any kind of repository of third party contributions. Should we have one? It would have to be the original contributor's responsibility to keep it updated for different Sage versions, otherwise we might as well go straight onto (2). A package in category (1) would come with no guarantees to work with later Sage versions, and no imprimatur (refereeing etc). For (2) we should have clearer instructions on what to do since it clearly isn't so obvious. As I was writing (1) above I could tell that others would probably not like it. In which case it is even more important that we make (2) easier. John On 14/01/2008, William Stein <[EMAIL PROTECTED]> wrote: > > On 1/14/08, D. Benjamin Antieau <[EMAIL PROTECTED]> wrote: > > To all, > > > > I've created a sage file to calculate, among other things, the Hodge numbers > > of an arbitrary complete intersection. Attached is the .sage file. I also > > attempted to create a .spkg file, but it does not seem to work. Mine > > contains simply a .py file that the install script puts it > > $SAGE_ROOT/local/bin. But, I cannot seem to use it from within sage. Any > > help on that front would be appreciated. On the other hand, loading the > > .sage file works fine. > > Probably you'll want to distribute this by just distributing the .sage file > with some instructions, and recommending that people attach the .sage file. > At least for now (i.e., what you're already doing). > > > The file itself is well-documented. I would love suggestions for further > > methods to add. For instance, at some point I will add the ability to > > compute the degrees of the top Chern classes of a threefold. > > > > I don't see putting this in sage at the moment, but it does lead to the > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > Why not? I think you should definitely aim to get this into the core > Sage distribution. See this recent thread on sage-support: > > http://groups.google.com/group/sage-support/browse_thread/thread/919e5ccadcacc094 > > > > question: should there be a CompleteIntersection class, which would inherit > > from AlgebraicScheme_subscheme_projective. If so, then I > > could put this code in that class in the characteristic zero case. > > This makes sense to me. > > > > > Ben Antieau > > > > Example: > > > > The Hodge numbers of a crazy fourfold. The list of integers is the list of > > degrees of the complete intersection. > > sage: hodge_numbers_ci([2,4,6,3,6,4,3,2,9,5],4) > > [ 1 0 0 0 2658146543] > > [ 0 1 0 22238665343 0] > > [ 0 0 42452753184 0 0] > > [ 0 22238665343 0 1 0] > > [ 2658146543 0 0 0 1] > > > > The file provides the following functions: > > chiy_characteristic_ci(degrees,index,yprecision,zprecision) > > hodge_numbers_ci(degrees,dimension) > > betti_numbers_ci(degrees,dimension) > > euler_characteristic_ci(degrees,dimension) > > topological_euler_characteristic_ci(degrees,dimension) > > arithmetic_genus_ci(degrees,dimension) > > geometric_genus_ci(degrees,dimension) > > [==arithmetic_genus_ci] > > K_squared_surface_ci(degrees,dimension) [computes the > > degree of K^2 of a complete intersection surface] > > c2_surface_ci(degrees,dimension) [computes the degree of > > the second Chern class of a complete intersection surface] > > > > > > > > > > > > > > -- > William Stein > Associate Professor of Mathematics > University of Washington > http://wstein.org > > > > -- John Cremona --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to [email protected] 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://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
