Hello, First of all, thanks to all of you !
Though differential algebra can be used to prepare differential systems before numerically integrate them, the package does not contain any function clearly related to numerical computations. Thus I would rather view it in the "algebraic" part of Sage. All the best, François 2012/11/26 Simon King <simon.k...@uni-jena.de> > Dear Charles, > > On 2012-11-26, Charles Bouillaguet <charles.bouillag...@gmail.com> wrote: > > We (at Lille, France) propose to integrate the DifferentialAlgebra into > SAGE. > > This package, which is already present in MAPLE, is the product of years > of > > work from François Boulier et al. on differential elimination. It relies > on > > François's C libraries. Its core is an implementation of the > Rosenfeld-Groebner > > algorithm, which rewrites systems of differential (or partial derivative) > > equations into potentially simpler ones. In algebraic terms, it > decomposes > > the radical of a differential ideal into the intersection of prime > differential > > ideals. > > That's a very valuable contribution, I think! > > > Next, it is not completely clear to us *where* to put this in sage. We > (somewhat > > arbitrarily) chose to put it in sage.calculus.DifferentialAlgebra, to > keep it > > close with the other functions dealing with differential equations, but > we agree > > that this is bizarre, because differential elimination is 100% algebraic. > > Differential algebra is a nice example where methods from one > mathematical field are applied to another mathematical field. > > So, why shouldn't one split the code accordingly and put it into > *two* parts of Sage? > > I'd suggest you implement the algebraic part in classes, say, > sage.algebras.differential_algebras.differential_algebra.DifferentialAlgebra > and > sage.algebras.differential_algebras.ideal.DifferentialAlgebraIdeal etc. > > And then, the application to the solution of differential equations may be > put into sage.calculus.desolvers.rosenfeld_groebner (or whatever > better name there is): After all, you can easily do "from > sage.algebras.differential_algebras import ..." in your DE-solver, > no matter where it is implemented. > > Actually, I think it might even be easier to review if the different > mathematical topics are cleanly separate in the code base. > > By the way, note that since more or less recently, the > g-algebras provided by Singular became wrapped in libsingular. > This is sage.rings.polynomial.plural.NCPolynomialRing_plural. > Would it make sense to define conversions back and forth between your > differential algebras and those in libsingular? > > > > Lastly, what is the right way to go ? experimental package ? > > optional package ? We confirmed that it compiles and works on > > Linux and Mac OS X. > > I think new stuff should first be experimental for a while, and then > promoted to an optional or even standard spkg. But there may be > exceptions. > > Best regards, > Simon > > > -- > You received this message because you are subscribed to the Google Groups > "sage-devel" group. > To post to this group, send email to sage-devel@googlegroups.com. > To unsubscribe from this group, send email to > sage-devel+unsubscr...@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-devel?hl=en. > > > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To post to this group, send email to sage-devel@googlegroups.com. To unsubscribe from this group, send email to sage-devel+unsubscr...@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel?hl=en.
