[SciPy-User] noob Needs guru for array manipulation

[josef.pktd at gmail.com]

On Sun, Dec 11, 2011 at 7:31 AM, Emmanuelle Gouillart
<emmanuelle.gouillart at normalesup.org> wrote:
> Hi,
>
> I'm not sure I understand your example (under 120 in algebraic
> or
> absolute value? Why don't you remove the last column which has 0 on
> the
> second line?), but the syntax would
> be
>
>>>> import numpy as
>>>> np
>>>> a = np.array([[1, 2, 3], [160, 30,
>>>> 125]])
>>>> b = a[:, a[1] >
>>>> 120]
>>>>
>>>> b
> array([[  1,
> 3],
>        [160,
> 125]])
>
> b = a[:, a[1] > 120] is called fancy indexing. For an introduction
> to
> numpy arrays, see for
> example
> http://scipy-lectures.github.com/intro/numpy/numpy.html

and

http://docs.scipy.org/doc/numpy/reference/arrays.indexing.html
http://mentat.za.net/numpy/intro/intro.html

Josef

>
> Cheers,
> Emmanuelle
>
> 2011/12/11 Jean-Baptiste BUTET <ashashiwa at gmail.com>
>>
>> Hi all :)
>>
>> I have this array :
>> [[  0.00000000e+00 ,  2.26757370e-05  , 4.53514739e-05 ,
>> 2.27548753e+00   , 2.27551020e+00  , 2.27553288e+00]
>>  [ -1.38700000e+03  , -1.51300000e+03 , -1.52600000e+03 ,
>> 3.39000000e+02,  1.11000000e+02   0.00000000e+00]
>>
>> I would like to remove couples where results in 2nd row are under 120 :
>>
>> [[  0.00000000e+00 ,  2.26757370e-05  , 4.53514739e-05 ,
>> 2.27548753e+00    , 2.27553288e+00]
>>  [ -1.38700000e+03  , -1.51300000e+03 , -1.52600000e+03 ,
>> 3.39000000e+02,     0.00000000e+00
>>
>> I don't really understand numpy array philosophia... so I need help here
>> :)
>>
>> Thanks.
>>
>> JB
>>
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>
>
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