John Cremona wrote: > 2009/5/7 Nick Alexander <ncalexan...@gmail.com>: >>> sage:RIF( 3 , 3.2 ) >>> 4.±1 >> -2 to unicode or whatever lets you type $\pm$. >> >> As for the fact that 4.? is confusing to people who know nothing about >> sage, that does not concern me in the slightest. I find lots of >> things that I know nothing about confusing! > > Me too, but I have absolutely no idea why RIF(3,3.2) is anywhere near > 4, so find this completely incomprehensible. Isn't it the interval > from 3.0 to 3.2? > > I have never used the RIF, mainly because I cannot understand its output.
It's a compact notation for the interval: [4.0-1 .. 4.0+1] = [3.0 .. 5.0] The question mark just means the interval goes from the number with last digit minus one to the number with last digit plus one. For example: 3.5? is the interval [3.4 .. 3.6] 3.293948? is the interval [3.293947 .. 3.293949] More documentation can be found by taking any element x of RIF and doing x.str? You can change the default back to printing an explicit interval by doing: sage: sage.rings.real_mpfi.printing_style='brackets' sage: RIF(3,3.2) [3.0000000000000000 .. 3.2000000000000002] sage: sage.rings.real_mpfi.printing_style='question' sage: RIF(3,3.2) 4.? Carl, could you comment on the difference between these two cases? sage: RIF(3,3.199999999999999) 3.1? sage: RIF(3,3.1999999999999999) 4.? Thanks, Jason -- Jason Grout --~--~---------~--~----~------------~-------~--~----~ 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 For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
