Mark Dickinson <[EMAIL PROTECTED]> writes: > On May 12, 11:15 am, Arnaud Delobelle <[EMAIL PROTECTED]> wrote: > >> But exp(y*log(x)) -> 1 as (x, y) -> (0, 0) along any analytic curve >> which is not the x=0 axis (I think at least - it seems easy to prove >> that given f and g analytic over R, f(x)*ln g(x) -> 0 as x -> 0 if >> f(0)=g(0)=0 and g(x)>0 in the neighbourhood of 0). > > Agreed. And this makes an excellent argument that if you're going to > choose a number for 0.0**0.0 then it's got to be 1. But I still don't > find it completely convincing as an argument that 0.0**0.0 should be > defined at all. > >> This should cover most practical uses? > > Maybe. But if you're evaluating x**y in a situation where x and y > represent physical quantities, or otherwise have some degree of error, > then you probably want to be warned if x and y both turn out to be > zero.
Yes. I'm not much of a physicist so I don't feel confident about this at all, but when you work out x**y, if x is a measured quantity with dimensions, then raising it to a power only makes sense if y is dimensionless and an integer, or maybe a rational with a small denominator (i.e. it makes sense to cube root a volume, but not a velocity). -- Arnaud -- http://mail.python.org/mailman/listinfo/python-list