inplace unary operations?
Is there a way to negate a boolean, or to change the sign of a float inplace ? Josef random thoughts
On Sat, Aug 30, 2014 at 6:43 PM, <josef.pktd@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) -n -- Nathaniel J. Smith Postdoctoral researcher - Informatics - University of Edinburgh http://vorpus.org
Random thoughts are the best kinds of thoughts! I didn't even know there was a np.negative() function! I will keep this card up my sleeve at work for one of those save-the-day moments in optimization. Cheers! Ben Root On Sat, Aug 30, 2014 at 1:45 PM, Nathaniel Smith <njs@pobox.com> wrote:
On Sat, Aug 30, 2014 at 6:43 PM, <josef.pktd@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)
-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
On Sat, Aug 30, 2014 at 7:39 PM, Benjamin Root <ben.root@ou.edu> wrote:
Random thoughts are the best kinds of thoughts! I didn't even know there was a np.negative() function!
Me neither, I had to look it up :-) -n -- Nathaniel J. Smith Postdoctoral researcher - Informatics - University of Edinburgh http://vorpus.org
On Sat, Aug 30, 2014 at 1:45 PM, Nathaniel Smith <njs@pobox.com> wrote:
On Sat, Aug 30, 2014 at 6:43 PM, <josef.pktd@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
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.pktd@gmail.com> wrote:
On Sat, Aug 30, 2014 at 1:45 PM, Nathaniel Smith <njs@pobox.com> wrote:
On Sat, Aug 30, 2014 at 6:43 PM, <josef.pktd@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
participants (4)
-
Benjamin Root -
josef.pktd＠gmail.com -
Nathaniel Smith -
Pierre Barbier de Reuille