'and' is not exactly an 'operator' (was Re: numpy.where() and multiple comparisons)

2014-01-18 Thread Terry Reedy
On 1/18/2014 3:50 AM, Peter Otten wrote: Unlike `&` `and` cannot be overridden (*), (*) I assume overriding would collide with short-cutting of boolean expressions. Yes. 'and' could be called a 'control-flow operator', but in Python it is not a functional operator. A functional binary op

Re: numpy.where() and multiple comparisons

2014-01-18 Thread Tim Roberts
Peter Otten <__pete...@web.de> wrote: >John Ladasky wrote: > >> On Friday, January 17, 2014 6:16:28 PM UTC-8, duncan smith wrote: >> >>> >>> a = np.arange(10) >>> >>> c = np.where((2 < a) & (a < 7)) >>> >>> c >>> (array([3, 4, 5, 6]),) >> >> Nice! Thanks! >> >> Now, why does the multiple co

Re: numpy.where() and multiple comparisons

2014-01-18 Thread Peter Otten
John Ladasky wrote: > On Friday, January 17, 2014 6:16:28 PM UTC-8, duncan smith wrote: > >> >>> a = np.arange(10) >> >>> c = np.where((2 < a) & (a < 7)) >> >>> c >> (array([3, 4, 5, 6]),) > > Nice! Thanks! > > Now, why does the multiple comparison fail, if you happen to know? 2 < a < 7 i

Re: numpy.where() and multiple comparisons

2014-01-17 Thread John Ladasky
On Friday, January 17, 2014 6:16:28 PM UTC-8, duncan smith wrote: > >>> a = np.arange(10) > >>> c = np.where((2 < a) & (a < 7)) > >>> c > (array([3, 4, 5, 6]),) Nice! Thanks! Now, why does the multiple comparison fail, if you happen to know? -- https://mail.python.org/mailman/listinfo/pyth

Re: numpy.where() and multiple comparisons

2014-01-17 Thread duncan smith
numpy.where() to select parts of arrays. I have encountered what I would consider to be a bug when you try to use where() in conjunction with the multiple comparison syntax of Python. Here's a minimal example: Python 3.3.2+ (default, Oct 9 2013, 14:50:09) [GCC 4.8.1] on linux Type

numpy.where() and multiple comparisons

2014-01-17 Thread John Ladasky
Hi folks, I am awaiting my approval to join the numpy-discussion mailing list, at scipy.org. I realize that would be the best place to ask my question. However, numpy is so widely used, I figure that someone here would be able to help. I like to use numpy.where() to select parts of arrays

Re: numpy.where

2009-04-11 Thread Lou Pecora
In article <747te7f1209a...@mid.individual.net>, Peter Pearson wrote: > On Thu, 09 Apr 2009 09:09:18 -0400, Lou Pecora wrote: > > > > Really, I've gotta RTFM. :-) > > Hey, if you find TFM, please tell me where it is. I haven't > found anything Fine. I even bought Travis Oliphant's book, > wh

Re: numpy.where

2009-04-10 Thread Lou Pecora
In article , Robert Kern wrote: > http://docs.scipy.org/doc/numpy/reference/arrays.indexing.html That helps, thanks. So I can RTFWP, too. :-) -- -- Lou Pecora -- http://mail.python.org/mailman/listinfo/python-list

Re: numpy.where

2009-04-10 Thread Peter Pearson
On Fri, 10 Apr 2009 02:39:46 -0500, Robert Kern wrote: > On 2009-04-09 22:40, Peter Pearson wrote: >> >> Hey, if you find TFM, please tell me where it is. I haven't >> found anything Fine. I even bought Travis Oliphant's book, >> which helps a little, but . . . > > http://docs.scipy.org/doc/nump

Re: numpy.where

2009-04-10 Thread Robert Kern
On 2009-04-09 22:40, Peter Pearson wrote: On Thu, 09 Apr 2009 09:09:18 -0400, Lou Pecora wrote: Thanks, Neil. Always something to learn. I've used Numpy for several years, but still have not plumbed the depths. Just tried this script and, yep, it works. arr=array([-1,1.0,2.2,-10.0,1.1

Re: numpy.where

2009-04-09 Thread Peter Pearson
On Thu, 09 Apr 2009 09:09:18 -0400, Lou Pecora wrote: > > Thanks, Neil. Always something to learn. I've used Numpy for several > years, but still have not plumbed the depths. Just tried this script > and, yep, it works. > > arr=array([-1,1.0,2.2,-10.0,1.1, 0.9,-0.9]) > cond= arr <

Re: numpy.where

2009-04-09 Thread Carl Banks
On Apr 9, 2:58 am, Neil Crighton wrote: > Carl Banks gmail.com> writes: > > > > >>> condition = (min_time <= time) & (time <= max_time) > > > >>> new_time = time[condition] > > > >>> new_energy = energy[condition] > > > Won't work: condition is an array of ones and zeros, but you need to > > inde

Re: numpy.where

2009-04-09 Thread Lou Pecora
In article , Neil Crighton wrote: > > I'm not sure exactly what you're trying to do, but maybe you want a boolean > array to select the right elements? So if time and energy are 1-d numpy arrays > of the same length: > > >>> condition = (min_time <= time) & (time <= max_time) > >>> new_time =

Re: numpy.where

2009-04-09 Thread Neil Crighton
Carl Banks gmail.com> writes: > > >>> condition = (min_time <= time) & (time <= max_time) > > >>> new_time = time[condition] > > >>> new_energy = energy[condition] > > Won't work: condition is an array of ones and zeros, but you need to > index the arrays with indices. So, add a call to nonzero

Re: numpy.where

2009-04-09 Thread Carl Banks
> to cut both arrays of time > > min<=time<=max  .   I've created a 2d array> with [time,energy] and I believe > numpy.where is what I am looking for, but > > haven't been able to get the > > > conditions in right for it to work.   > > I'

Re: numpy.where

2009-04-09 Thread Neil Crighton
ted a 2d array > with [time,energy] and I believe numpy.where is what I am looking for, but haven't been able to get the > conditions in right for it to work. I'm not sure exactly what you're trying to do, but maybe you want a boolean array to select the right elements? So if

numpy.where

2009-04-09 Thread heidi taynton
Hi, I'm fairly new to programming and am having a probably cutting my arrays. I have two different 1d arrays, one of time, and the second energy.I want to cut both arrays of time min<=time<=max . I've created a 2d array with [time,energy] and I believe numpy.wh