Mark Wiebe wrote: > Speaking of which, would we make the NA value be false? > > For booleans, it works out like this: > > http://en.wikipedia.org/wiki/Ternary_logic#Kleene_logic
That's pretty cool! > In R, trying to test the truth value of NA ("if (NA) ...") raises an > exception. Adopting this behavior seems reasonable to me. I'm not so sure. the other president is Python, where None is interpreted as False. In general, in non-numpy code, I use None to mean "not set yet" or "I'm not sure", or, whatever. It's pretty useful to have it be false. However, I also do: if x is not None: rather than- if x: so as to be unambiguous about what I'm testing for (and because if x == 0, I don't want the test to fail), so I guess: if arr[i] is np.NA: would be perfectly analogous. -Chris > -Mark > > > > -Chris > > > -- > Christopher Barker, Ph.D. > Oceanographer > > Emergency Response Division > NOAA/NOS/OR&R (206) 526-6959 <tel:%28206%29%20526-6959> > voice > 7600 Sand Point Way NE (206) 526-6329 <tel:%28206%29%20526-6329> fax > Seattle, WA 98115 (206) 526-6317 <tel:%28206%29%20526-6317> > main reception > > chris.bar...@noaa.gov <mailto:chris.bar...@noaa.gov> > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org <mailto:NumPy-Discussion@scipy.org> > http://mail.scipy.org/mailman/listinfo/numpy-discussion > > > > ------------------------------------------------------------------------ > > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R (206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception chris.bar...@noaa.gov _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion