On Wed, Jul 6, 2011 at 5:03 PM, Benjamin Root <[email protected]> wrote:
> On Wednesday, July 6, 2011, Dag Sverre Seljebotn > <[email protected]> wrote: > > On 07/06/2011 08:25 PM, Christopher Barker wrote: > >> Mark Wiebe wrote: > >>> 1) NA vs IGNORE and bitpattern vs mask are completely independent. Any > >>> combination of NA as bitpattern, NA as mask, IGNORE as bitpattern, and > >>> IGNORE as mask are reasonable. > >> > >> Is this really true? if you use a bitpattern for IGNORE, haven't you > >> just lost the ability to get the original value back if you want to stop > >> ignoring it? Maybe that's not inherent to what an IGNORE means, but it > >> seems pretty key to me. > > > > There's the question of how reductions treats the value. IIUC, IGNORE as > > bitpattern would imply that reductions treat the value as 0, which is a > > question orthogonal to whether the value can possibly be unmasked or not. > > > > Dag Sverre > > > > Just because we are trying to be exact here, the reductions would > treat IGNORE as the operation's identity. Therefore, for addition, it > would be treated like 0, but for multiplication, it is treated like a > 1. > > Ben Root > Yes. But, as discussed on another thread, that can lead to unexpected results when it's propagated through several operations. > _______________________________________________ > NumPy-Discussion mailing list > [email protected] > http://mail.scipy.org/mailman/listinfo/numpy-discussion >
_______________________________________________ NumPy-Discussion mailing list [email protected] http://mail.scipy.org/mailman/listinfo/numpy-discussion
