David M. Cooke wrote: > Peter Hansen <[EMAIL PROTECTED]> writes: > > >>Steven D'Aprano wrote: >> >>>Dealing with numeric literals with lots of digits is >>>a real (if not earth-shattering) human interface problem: it is hard for >>>people to parse long numeric strings. >> >>I'm totally unconvinced that this _is_ a real problem, if we define >>"real" as being even enough to jiggle my mouse, let alone shattering the >>planet. >> >>What examples does anyone have of where it is necessary to define a >>large number of large numeric literals? Isn't it the case that other >>than the odd constants in various programs, defining a large number of >>such values would be better done by creating a data file and parsing >>it? > > > One example I can think of is a large number of float constants used > for some math routine. In that case they usually be a full 16 or 17 > digits. It'd be handy in that case to split into smaller groups to > make it easier to match with tables where these constants may come > from. Ex: > > def sinxx(x): > "computes sin x/x for 0 <= x <= pi/2 to 2e-9" > a2 = -0.16666 66664 > a4 = 0.00833 33315 > a6 = -0.00019 84090 > a8 = 0.00000 27526 > a10= -0.00000 00239 > x2 = x**2 > return 1. + x2*(a2 + x2*(a4 + x2*(a6 + x2*(a8 + x2*a10)))) > > (or least that's what I like to write). Now, if I were going to higher > precision, I'd have more digits of course. > Right, this is clearly such a frequent use case it's worth changing the compiler for.
regards Steve -- Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC www.holdenweb.com PyCon TX 2006 www.python.org/pycon/ -- http://mail.python.org/mailman/listinfo/python-list
