A. M. Archibald wrote: > On 08/11/06, Pierre GM <[EMAIL PROTECTED]> wrote: > > >> I like your idea, but not its implementation. If MA.masked_singleton is >> defined as an object, as you suggest, then the dtype of the ndarray it is >> passed to becomes 'object', as you pointed out, and that is not something one >> would naturally expec, as basic numerical functions don't work well with >> the >> 'object' dtype (just try N.sqrt(N.array([1],dtype=N.object)) to see what I >> mean). >> Even if we can construct a mask rather easily at the creation of the masked >> array, following your 'a==masked' suggestion, we still need to get the dtype >> of the non-masked section, and that doesn't seem trivial... >> > > A good candidate for "should be masked" marked is NaN. It is supposed > to mean, more or less, "no sensible value". Unfortunately, integer > types do not have such a special value. It's also conceivable that > some user might want to keep NaNs in their array separate from the > mask. Finally, on some hardware, operations with NaN are very slow (so > leaving them in the array, even masked, might not be a good idea). > It has always been my experience (on various flavors or Pentium) that operating on NANs is extremely slow. Does anyone know on what hardware NANs are *not* slow? Of course it's always possible I just never notice NANs on hardware where they aren't slow.
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