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,
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
On Sat, Aug 30, 2014 at 6:43 PM,
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
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
On Sat, Aug 30, 2014 at 6:43 PM,
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,
On Sat, Aug 30, 2014 at 1:45 PM, Nathaniel Smith
wrote: On Sat, Aug 30, 2014 at 6:43 PM,
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)
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Benjamin Root
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josef.pktd@gmail.com
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Nathaniel Smith
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Pierre Barbier de Reuille