On Thu, Aug 28, 2008 at 10:59 PM, mabshoff <[EMAIL PROTECTED]> wrote: > > > > On Aug 28, 10:47 pm, "William Stein" <[EMAIL PROTECTED]> wrote: >> On Thu, Aug 28, 2008 at 8:57 AM, Roger <[EMAIL PROTECTED]> wrote: >> >> > solve([x==0, 1-exp(y)==0],x,y) >> > returns the empty set, although (0,0) is an obvious solution. This >> > occurs also for other simple combinations involving exp, as well as >> > for >> > solve([y*sin(x)==0, cos(x)==0],x,y) >> >> > What am I doing wrong? Thanks. (Sage 3.0.2 on Mac OSX) >> >> Sage uses Maxima's solve command, and Maxima's solve >> command is pretty wimpy, and we (Sage developers) intend >> to write our own new solve command that can deal with >> more general equations. >> >> Here's an illustration of maxima not solving the above equations >> >> sage: !maxima >> (%i2) solve([x=0, 1-exp(y)=0],[x,y]); >> (%o2) [] >> (%i3) solve([y*sin(x)=0, cos(x)=0],[x,y]); >> (%o3) [] > > Yeah, and it is also broken in the latest Maxima (since William might > have used the Maxima from Sage 3.1.1):
If you read the docs for Maxima's solve, then I don't think "broken" is the right word. It's more that Maxima's solve simply isn't that sophisticated of a command, and doesn't claim to be. The only real solutions is for some sage developers to write a whole solve package, which is going to probably be an interesting project. The first step would be to replicate Maxima's functionality, at least. William > > Maxima 5.16.2 http://maxima.sourceforge.net > Using Lisp CLISP 2.46 (2008-07-02) > Distributed under the GNU Public License. See the file COPYING. > Dedicated to the memory of William Schelter. > The function bug_report() provides bug reporting information. > (%i1) solve([x=0, 1-exp(y)=0],[x,y]); > (%o1) [] > (%i2) solve([y*sin(x)=0, cos(x)=0],[x,y]); > (%o2) [] > (%i3) > > Since Robert Dodier is not subscribed to sage-support I am CCin him > here. > >> You can read the help on maxima's solve, if you want to get >> a sense of its limitations. >> >> sage: maxima.solve? >> >> William > > Cheers, > > Michael > > > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
