[Numpy-discussion] converting scalar to array with dimension 1
Fri Mar 30 16:43:42 CDT 2007
On 3/31/07, Pierre GM <firstname.lastname@example.org> wrote:
> > I think you'll want to add the copy=False arg if you go that route, or
> > else you'll end up with something that's much slower than atleast_1d
> > for any array that gets passed in. :-)
> Yep indeed. We can also add the subok=True flag.
> > a = array(a, copy=0,ndmin=1)
> > Anyway, sounds like premature optimization to me.
> Ah, prematurity depends on the context, doesn't it ? Isn't there some famous
> quote about two-liners ? Here, we have a function that does little more but
> calling array(x,subok=True, copy=False, ndmin=1) in a loop. Is skipping the
> loop for some very specific applications really premature ?
Perhaps not. But the OP was definitely not talking about some
I find asarray_1d et al to be clearer to read, and easier to type than
the array call with all the flags. So barring some specific
performance critical situation, I go with asarray_1d. Actually I
didn't realize that it had a loop in it, so thanks for pointing that
out. I thought it was just and alias for array with some args.
> For example, I
> tend to use more and more the subok=True flag instead of 'asanyarray': is
> there any 'official' recommendation about this ?
Actually, I tend to use subok=False more and more. Matrix, despite
being a subclass of ndarray, is too incompatible with ndarray to
really mix and match most of the time. So it seems safest just to
force everything to be a bog-stock ndarray. I made some convenience
functions that provide the right args to array for my own use.
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