Yes, the creation of the tmp *is* the creation of a new NumPy array. So, it is as expensive.
Travis -- Travis Oliphant (on a mobile) 512-826-7480 On Jun 28, 2012, at 12:44 AM, srean <srean.l...@gmail.com> wrote: >> Yes it does. If you want to avoid this extra copy, and have a >> pre-existing output array, you can do: >> >> np.add(a, b, out=c) >> >> ('+' on numpy array's is just a synonym for np.add; np.add is a ufunc, >> and all ufunc's accept this syntax: >> http://docs.scipy.org/doc/numpy/reference/ufuncs.html >> ) > > > Is the creation of the tmp as expensive as creation of a new numpy > array or is it somewhat lighter weight (like being just a data > buffer). I sometimes use the c[:] syntax thinking I might benefit from > numpy.array re-use. But now I think that was misguided. > _______________________________________________ > NumPy-Discussion mailing list > 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