Re: [Numpy-discussion] Choosing between NumPy and SciPy functions
I would add one element to the discussion: for some (odd) reasons, SciPy is lacking the functions `rfftn` and `irfftn`, functions using half the memory space compared to their non-real equivalent `fftn` and `ifftn`. However, I haven't (yet) seriously tested `scipy.fftpack.fftn` vs. `np.fft.rfftn` to check if there is a serious performance gain (beside memory usage). Cheers, Pierre On Tue Oct 28 2014 at 10:54:00 Stefan van der Walt ste...@sun.ac.za wrote: Hi Michael On 2014-10-27 15:26:58, D. Michael McFarland dm...@dmmcf.net wrote: What I would like to ask about is the situation this illustrates, where both NumPy and SciPy provide similar functionality (sometimes identical, to judge by the documentation). Is there some guidance on which is to be preferred? I could argue that using only NumPy when possible avoids unnecessary dependence on SciPy in some code, or that using SciPy consistently makes for a single interface and so is less error prone. Is there a rule of thumb for cases where SciPy names shadow NumPy names? I'm not sure if you've received an answer to your question so far. My advice: use the SciPy functions. SciPy is often built on more extensive Fortran libraries not available during NumPy compilation, and I am not aware of any cases where a function in NumPy is faster or more extensive than the equivalent in SciPy. If you want code that falls back gracefully when SciPy is not available, you may use the ``numpy.dual`` library. Regards Stéfan ___ 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
Re: [Numpy-discussion] inplace unary operations?
Just to point out another solution to change the sign: arr *= -1 Both solutions take the same time on my computer. However, the boolean equivalent: arr ^= True is a lot slower than using negative. My two cents ... -- Dr. Barbier de Reuille, Pierre Institute of Plant Sciences Altenbergrain 21, CH-3013 Bern, Switzerland http://www.botany.unibe.ch/associated/systemsx/index.php On 31 August 2014 15:31, josef.p...@gmail.com wrote: On Sat, Aug 30, 2014 at 1:45 PM, Nathaniel Smith n...@pobox.com wrote: On Sat, Aug 30, 2014 at 6:43 PM, josef.p...@gmail.com wrote: Is there a way to negate a boolean, or to change the sign of a float inplace ? np.logical_not(arr, out=arr) np.negative(arr, out=arr) Thanks Nathaniel. np.negative might save a bit of memory and time when we have to negate the loglikelihood all the time. Josef -n -- Nathaniel J. Smith Postdoctoral researcher - Informatics - University of Edinburgh http://vorpus.org ___ 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 ___ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
