On Tue, May 27, 2008 at 3:28 PM, Charles R Harris <[EMAIL PROTECTED]> wrote:
> > > On Tue, May 27, 2008 at 2:40 PM, Travis E. Oliphant < > [EMAIL PROTECTED]> wrote: > >> Charles R Harris wrote: >> > >> > >> > On Tue, May 27, 2008 at 2:10 PM, Travis E. Oliphant >> > <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>> wrote: >> > >> > Stéfan van der Walt wrote: >> > > Did this change recently? >> > > >> > > In [33]: np.__version__ >> > > Out[33]: '1.1.0.dev5211' >> > > >> > > In [34]: np.minimum(np.uint8(164), np.uint64(12807)).dtype >> > > Out[34]: dtype('uint64') >> > > >> > > But yes, that looks like it should return a uint8. >> > > >> > This discussion is really moot unless a proposal for how to handle >> > different casting rules for different ufuncs is proposed. Right >> now, >> > the type-promotion rules are generic and do not depend on the >> > ufunc only >> > on coercion rules for the mixed types. >> > >> > One problem with a casting-rules-per-ufunc approach is that it >> > makes it >> > harder to add new types and have them fit in to the casting >> structure >> > (which is currently possible now). Some mechanism for allowing the >> > types to plug-in to the per-ufunc rules would be needed. >> > >> > These are not impossible things, just a bit of work and not on my >> > personal priority list. >> > >> > >> > Not everything follows those rules, however. So I have put these >> > things up for review so that we can agree on what the are. Of >> > particular concern in my mind are the bitwise and shift operators >> > which currently work in a counter intuitive manner. >> >> Right now, the only complete description of the rules is the code that >> implements them. So, from that perspective, yes everything follows >> those rules ;-) >> > > So the segfaults are defined behavior? ;) It's like pulling teeth without > anesthesia to get these things defined and everyone is going to think I'm an > a-hole. It's a dirty job, but someone has got to do it. > > What about abs(-128) returning a negative number for int8? Might it not be > better to return the corresponding unsigned type? Can't check that at the > moment, as I'm trying to get 64 bit Ubuntu installed on a software raid1 > partition for further checks, and Ubuntu overwrote my MBR without asking. > It's a traditional Ubuntu thing. > Yep, abs fails: In [1]: abs(array([-128,-128], dtype=int8)) Out[1]: array([-128, -128], dtype=int8) Chuck
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