Can global variable be passed into Python function?
roy at panix.com
Sat Mar 1 01:02:44 CET 2014
In article <0b414429-74ee-45dd-9465-c87e98c362f2 at googlegroups.com>,
"Mark H. Harris" <harrismh777 at gmail.com> wrote:
> On Friday, February 28, 2014 3:03:25 PM UTC-6, Marko Rauhamaa wrote:
> > Marko
> ... and between me and you, here is a snip from dmath.py from the atan(x)
> if (n**2 < D(1)):
> a = __atan__(n)
> elif (n == D(1)):
> a = gpi/4
> elif (n == D(-1)):
> a = -(gpi/4)
> elif (n < D(-1)):
> a = __atan__Lt_neg1__(n)
> a = __atan__Gt_1__(n)
> This if--elif--else is not only ugly, its just not readable either, and
> besides that, its not elegant, nor is it humanly helpful... its does
> work though, and its absolutely necessary. ugh.
> First, its not immediately clear what it does. Well, there isn't just one
> atan(x) routine, there are at least four of them, depending on whether
> you're a purist, and they must be selected.
This kind of stuff is pretty common in numerical code. Depending on the
sign/magnitude/quadrant/whatever of the argument, you'll want to use one
of several algorithms to minimize roundoff error, etc.
But, how would this be any nicer with switch?
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