On 2013-08-19, Vincent Knight <[email protected]> wrote: > --001a1133aa8653f2ed04e4510b09 > Content-Type: text/plain; charset=ISO-8859-1 > > Thanks for the answer kcrisman but I'm afraid I'm still not sure I > understand. > > If by 'unsigned infinity' you mean that Sage is returning positive infinity > (but assuming that there is no need to return the '+') then I agree but I > also still don't think that this is the required behaviour right? The > undirected limit should is not defined (so Sage should return that the > 'undefined') and given the help file, the output is a bit confusing... If > I'm missing something please do forgive me :)
IMHO "unsigned infinity" simply means NaN (Not a Number). Correct me if I'm wrong here. Dima > > Vince > > > On 19 August 2013 19:17, kcrisman <[email protected]> wrote: > >> >> >> On Monday, August 19, 2013 1:55:04 PM UTC-4, Vince wrote: >>> >>> When computing the limit of a function I don't quite seem to be getting >>> the behaviour that I expected. >>> >>> --- >>> sage: f(x) = 1 / x >>> sage: print f.limit(x=0) >>> sage: print f.limit(x=0, dir='minus') >>> --- >>> >>> The first limit returns infinity, but I would expect it to return that >>> the limit is not defined. >>> >> >> I think we have an unsigned infinity and a signed infinity. It should >> return the former, from Maxima. >> >> >> >> >>> The second (directional) limit confirms this (it returns -infinity). I >>> was assuming that the default 'direction' for a limit is None and that a >>> two directional limit would be computed (which in this case does not >>> exist). Here's some of the help file that shows why I am perhaps confused: >>> >>> --- >>> INPUT: >>> >>> - ``dir`` - (default: None); dir may have the value >>> 'plus' (or '+' or 'right') for a limit from above, >>> 'minus' (or '-' or 'left') for a limit from below, or may be omitted >>> (implying a two-sided limit is to be computed). >>> --- >>> >>> If anyone could clarify this I'd appreciate it. >>> >>> Vince >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "sage-support" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/sage-support. >> For more options, visit https://groups.google.com/groups/opt_out. >> > > > > -- > Dr Vincent Knight > Cardiff School of Mathematics > Senghennydd Road, > Cardiff > CF24 4AG > (+44) 29 2087 5548 > www.vincent-knight.com > +Vincent Knight > @drvinceknight > Skype: drvinceknight > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/groups/opt_out.
