Maybe this is only a minor point, but having x predefined means that in many doctests where a number field is needed (and there are a lot), the doctest starts with something like
sage: K.<a> = NumberField(x^3-2) which means that when the doctest is run, there is an unnecessary overhead involced since x^3-2 is evaluated in the SR and then converted to a polynomial (or somthing like that). I would be interested to see how many doctests fail if the automattice predefinition iof x is turned off. How might that be done? John On 11 May 2012 08:53, Keshav Kini <keshav.k...@gmail.com> wrote: > Nils Bruin <nbr...@sfu.ca> writes: >> On May 11, 12:16 am, Simon King <simon.k...@uni-jena.de> wrote: >>> IIRC, the canonical answer to the request "do not predefine x" is: >>> "That's not gonna happen, because way too many people expect to have a >>> variable x handy." >> >> Or perhaps: >> >> "If you don't like x predefined, then put the command 'del x' in .sage/ >> init.sage". >> >> While reasonable defaults are nice to have, it's even more important >> to make it easy for people to tweak the setting to their liking -- and >> it is easy. > > I think those two goals are sort of orthogonal. My objection to > predefining x is not because I personally find it annoying to have it > defined. Actually I find it useful too. It's the predefinition of x *as > a default* that bothers me, because of what it suggests about our > official system design specs. Conversely I'm sure you can imagine that I > have stuff in my init.sage which I would never argue for making a > default setting. So "If you don't like x predefined then get rid of it > in your init.sage" does not really address my complaint, I think. > > Oh well. > > Also in regards to your wording "reasonable defaults", I would point out > that defining x as a variable is not exactly a choice of a default for a > setting. Choosing to make n() output 53 bits of precision unless > otherwise specified is a default - it's a choice of one setting among > many possible choices, all of which are more or less equally plausible > to some extent. Choosing to make polynomials print in grevlex term order > is also a default. Predefining x as a symbolic variable, on the other > hand, is a bolt from the blue and not a default setting chosen among > similar other options. I think that makes it more reasonable to talk > about changing or removing it. > > -Keshav > > ---- > Join us in #sagemath on irc.freenode.net ! > > -- > 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 > URL: http://www.sagemath.org -- 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 URL: http://www.sagemath.org
