Hi Nils, In my experience it often seems like it often seems desirable to have a > "field" R that tries to behave a little closer to being a field, but upon > closer inspection, the nasty implementation details of floating point > numbers will require for any somewhat serious application a special > treatment anyway. > > Thus, before embarking on the laborious task of trying to program such a > field, I recommend you first try to find a non-trivial scenario that would > genuinely benefit from this work. >
Perhaps the constructor of RR should accept a flag specifying whether overflow, division by zero, etc. should raise exceptions or silently return +/- infinity or NaN. I think it wouldn't really be that much work (see Paul Zimmermann's comment about MPFR internally raising exceptions), although I said "a case could be made" and not "I want to implement this". Anyway, I do think there are realistic possibilities for needless confusion when using Sage as a tool to teach people about calculus. Say I am a student who wants to experiment with integration. It is easy to write some Sage code to approximate \int_0^1 f(x) dx using the trapezium rule. Then if I apply this unsuspectingly to f(x) = x^(-1/2), the outcome will be infinity (for any step width) since f(0) = infinity. Since no zero division error occurs, I could be led to believe that the value of the integral is infinity instead of 2, and I could even "explain" this to myself by noticing that f(x) takes the value infinity somewhere. Peter -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/groups/opt_out.
