Surely one option would be to implement elliptic_e ourselves in Sage; or use the pari library, if it is there? Some elliptic functions are there. If elliptic_e is one of the ones which can be computed efficiently usn the AGM it should not be hard.
John 2009/8/10 Juan Jose Garcia-Ripoll <juanjose.garciarip...@googlemail.com>: > > On Mon, Aug 10, 2009 at 9:42 AM, Dr. David > Kirkby<david.kir...@onetel.net> wrote: >> You probably see my previous posts on the fact that elliptic_e is giving >> incorrect results on SPARC hardware using ECL. If not, >> http://sagetrac.org/sage_trac/ticket/6716 >> has the details. > > I will remove maxima mailing list from this answer to spare me the > usual despective comments about ECL. > >> Is there anything else that could be suspected, and so narrow down the >> list of possible causes somewhat? >> * Hardware fault on the particular machine. >> * Design flaw in Sun UltraSPARC CPU >> * ECL >> * Solaris library bug >> * Maxima >> * gcc >> * I screwed up compiling Maxima or ECL. > > There are two potential sources of error I can think of. One is the > fact that special function computations with integers/rationals will > be done using short floats in Common-Lisp. It may well be that at some > places this coercion is taking place, etc, etc. > > The other possibility is that ECL is inlining the functions using the > C library. I systematically appreciate errors in rounding, results and > accuracy due to this. See http://ecls.sourceforge.net/logs.html and > how the failed ansi tests change from platform to platform. > > I do not know whether this is essential to using the C library, or > whether it is associated to the code that the compiler generates. For > instance, gcc may produce code that is less accurate than the C > library itself, or it may use _more_ accuracy than expected by the > IEEE standard. > > The way to determine whether it is the compiled code that is > responsible is to execute the same function interpreted and compiled. > But of course, for that we need the particular expression that Maxima > is using. > > Juanjo > > -- > Instituto de Física Fundamental, CSIC > c/ Serrano, 113b, Madrid 28006 (Spain) > http://juanjose.garciaripoll.googlepages.com > > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
