[AstroPy] How can I take the index of "True" value and minimum "True" in list with python ?
Trey Wenger
tvw2pu at virginia.edu
Tue Apr 8 12:45:53 EDT 2014
Hi again, Thuong.
I think I understand what you are tying to do. You are tying to find the
minimum of abs(E - gE0) for every sub-array in gE0. This is what I would do:
min_indicies = [abs(E - my_gE0).argmin() for my_gE0 in gE0]
So, min_indicies[0] is the index of the minimum of abs(E-gE0[0]),
min_indicies[1] is the index of the minimum of abs(E - gE0[1]), etc.
Hope this helps,
Trey
On Tue, Apr 8, 2014 at 12:20 PM, THƯỜNG Hoàng Đức <
hoangthuong.hust at gmail.com> wrote:
> thank you Trey,
>
> How can i find the minimum value for different location in the list. Let
> me show you more detail: (I am sorry, it is long )
>
> I have:
> In [15]: E
> Out[15]:
> array([ 1.00000000e-03, 2.78255940e-03, 7.74263683e-03,
> 2.15443469e-02, 5.99484250e-02, 1.66810054e-01,
> 4.64158883e-01, 1.29154967e+00, 3.59381366e+00,
> 1.00000000e+01])
>
> In [16]: gE0
> Out[16]:
> array([[ 1.00000000e-03, 1.00000000e-03, 1.00000000e-03,
> 1.00000000e-03, 1.00000000e-03, 1.00000000e-03,
> 1.00000000e-03, 1.00000000e-03, 1.00000000e-03,
> 1.00000000e-03],
> [ 5.99484250e-03, 5.99484250e-03, 5.99484250e-03,
> 5.99484250e-03, 5.99484250e-03, 5.99484250e-03,
> 5.99484250e-03, 5.99484250e-03, 5.99484250e-03,
> 5.99484250e-03],
> [ 3.59381366e-02, 3.59381366e-02, 3.59381366e-02,
> 3.59381366e-02, 3.59381366e-02, 3.59381366e-02,
> 3.59381366e-02, 3.59381366e-02, 3.59381366e-02,
> 3.59381366e-02],
> [ 2.15443469e-01, 2.15443469e-01, 2.15443469e-01,
> 2.15443469e-01, 2.15443469e-01, 2.15443469e-01,
> 2.15443469e-01, 2.15443469e-01, 2.15443469e-01,
> 2.15443469e-01],
> [ 1.29154967e+00, 1.29154967e+00, 1.29154967e+00,
> 1.29154967e+00, 1.29154967e+00, 1.29154967e+00,
> 1.29154967e+00, 1.29154967e+00, 1.29154967e+00,
> 1.29154967e+00],
> [ 1.18292276e+00, 1.20239338e+00, 1.26419499e+00,
> 1.38016526e+00, 1.57688572e+00, 1.91417885e+00,
> 2.55149610e+00, 4.10977947e+00, 7.74263683e+00,
> 7.74263683e+00],
> [ 2.77831168e-01, 2.82126806e-01, 2.95703802e-01,
> 3.20921794e-01, 3.62928377e-01, 4.32761236e-01,
> 5.56895376e-01, 8.15796501e-01, 1.61701932e+00,
> 4.64158883e+01],
> [ 7.88832931e-02, 8.01002871e-02, 8.39462486e-02,
> 9.10876310e-02, 1.02977169e-01, 1.22725700e-01,
> 1.57778342e-01, 2.30672383e-01, 4.54431889e-01,
> 2.78255940e+02],
> [ 4.46767553e-02, 4.53659668e-02, 4.75440123e-02,
> 5.15882797e-02, 5.83213761e-02, 6.95047231e-02,
> 8.93535809e-02, 1.30626292e-01, 2.57284143e-01,
> 1.66810054e+03],
> [ 4.84949885e-02, 4.92431017e-02, 5.16072881e-02,
> 5.59971873e-02, 6.33057070e-02, 7.54447993e-02,
> 9.69899542e-02, 1.41789797e-01, 2.79271195e-01,
> 1.00000000e+04]])
>
> In [25]: (abs(E - gE0) < 0.02)
> Out[25]:
> array([[ True, True, True, False, False, False, False, False, False,
> False],
> [ True, True, True, True, False, False, False, False, False,
> False],
> [False, False, False, True, False, False, False, False, False,
> False],
> [False, False, False, False, False, False, False, False, False,
> False],
> [False, False, False, False, False, False, False, True, False,
> False],
> [False, False, False, False, False, False, False, False, False,
> False],
> [False, False, False, False, False, False, False, False, False,
> False],
> [False, False, False, False, False, False, False, False, False,
> False],
> [False, False, False, False, True, False, False, False, False,
> False],
> [False, False, False, False, True, False, False, False, False,
> False]], dtype=bool)
>
> In [26]: abs(E - gE0)
> Out[26]:
> array([[ 0.00000000e+00, 1.78255940e-03, 6.74263683e-03,
> 2.05443469e-02, 5.89484250e-02, 1.65810054e-01,
> 4.63158883e-01, 1.29054967e+00, 3.59281366e+00,
> 9.99900000e+00],
> [ 4.99484250e-03, 3.21228310e-03, 1.74779432e-03,
> 1.55495044e-02, 5.39535825e-02, 1.60815211e-01,
> 4.58164041e-01, 1.28555482e+00, 3.58781882e+00,
> 9.99400516e+00],
> [ 3.49381366e-02, 3.31555772e-02, 2.81954998e-02,
> 1.43937897e-02, 2.40102884e-02, 1.30871917e-01,
> 4.28220747e-01, 1.25561153e+00, 3.55787553e+00,
> 9.96406186e+00],
> [ 2.14443469e-01, 2.12660910e-01, 2.07700832e-01,
> 1.93899122e-01, 1.55495044e-01, 4.86334153e-02,
> 2.48715414e-01, 1.07610620e+00, 3.37837019e+00,
> 9.78455653e+00],
> [ 1.29054967e+00, 1.28876711e+00, 1.28380703e+00,
> 1.27000532e+00, 1.23160124e+00, 1.12473961e+00,
> 8.27390782e-01, 1.33226763e-15, 2.30226400e+00,
> 8.70845033e+00],
> [ 1.18192276e+00, 1.19961082e+00, 1.25645235e+00,
> 1.35862091e+00, 1.51693729e+00, 1.74736880e+00,
> 2.08733721e+00, 2.81822980e+00, 4.14882316e+00,
> 2.25736317e+00],
> [ 2.76831168e-01, 2.79344246e-01, 2.87961166e-01,
> 2.99377447e-01, 3.02979952e-01, 2.65951182e-01,
> 9.27364927e-02, 4.75753164e-01, 1.97679434e+00,
> 3.64158883e+01],
> [ 7.78832931e-02, 7.73177277e-02, 7.62036117e-02,
> 6.95432841e-02, 4.30287441e-02, 4.40843535e-02,
> 3.06380541e-01, 1.06087728e+00, 3.13938177e+00,
> 2.68255940e+02],
> [ 4.36767553e-02, 4.25834074e-02, 3.98013755e-02,
> 3.00439328e-02, 1.62704897e-03, 9.73053306e-02,
> 3.74805302e-01, 1.16092337e+00, 3.33652952e+00,
> 1.65810054e+03],
> [ 4.74949885e-02, 4.64605423e-02, 4.38646513e-02,
> 3.44528404e-02, 3.35728195e-03, 9.13652544e-02,
> 3.67168929e-01, 1.14975987e+00, 3.31454247e+00,
> 9.99000000e+03]])
>
> and Finaly:
> At the first red line. I would to take the index[2] of value
> 1.78255940e-03 (minimum)
> At the second line. I would to take the index of value 1.74779432e-03
> (minimum)
> .
> .
> .
>
> May you try to help me
>
> Thuong,
>
>
> 2014-04-08 16:09 GMT+02:00 Trey Wenger <tvw2pu at virginia.edu>:
>
>> Hi Thuong,
>>
>> I would do this
>>
>> index = abs(gE0[:,0] - ek).argmin()
>>
>> .argmin() returns the index at which the previous argument is smallest.
>> Now, gE0[;,0][index] will be the value of gE0[;,0] closest to ek.
>>
>> For example,
>>
>> IPy> x = np.array([1.1, 2.3, 4.4])
>> IPy> y = 2.2
>> IPy> index = np.abs(x-y).argmin()
>> IPy> index
>> Out> 1
>> IPy> x[index]
>> Out> 2.3
>> IPy> # this is the value in x closest to y
>>
>> Cheers,
>> Trey
>>
>>
>> On Tue, Apr 8, 2014 at 9:57 AM, THƯỜNG Hoàng Đức <
>> hoangthuong.hust at gmail.com> wrote:
>>
>>> Dear AstroPyer,
>>>
>>> I have problem with ideals !
>>> Firstly, I have two array. "ek" (one dimension - value in logspace) and
>>> "gE0[]" (two dimension - value in logspace). After that I scan value ek in
>>> array gE0 to find the equal value, It mean that abs(ek-gE0[:,0]) = 0. Due
>>> to the numerical that in logspace, it can not equal zeros(There are some
>>> point near the 0), and then I put the error for example err < 0.08 >>>>
>>> abs(ek-gE0[:,0]) < 0.08. You can see the value below. The result I would to
>>> take is True but it has several value < 0.08 also true, then how can i take
>>> smallest if have several True.
>>>
>>>
>>> In [53]: abs(ek-gE0[:,0]) < 0.08
>>> Out[53]: array([False, True, False, False, False, False, True, True,
>>> True, True], dtype=bool)
>>>
>>> ek = 0.1
>>> In [52]: gE0[:,0]
>>> Out[52]:
>>> array([ 0.01 , 0.04641589, 0.21544347, 1. , 1.93593016,
>>> 0.51306049, 0.15479754, 0.06105322, 0.04410808, 0.04849499])
>>>
>>> How can i take only the value: i = 1, value = 0.04641589 and i = 9,
>>> value = 0.04410808
>>>
>>>
>>> Thankyou very muck
>>>
>>> Merci beaucoup,
>>>
>>> Thuong
>>>
>>> ================================================
>>> THUONG Hoang Duc
>>>
>>> Université des Sciences et des Technologies de Hanoi(USTH)
>>> University of Science and Technology of Hanoi(USTH)
>>> Hanoi University of Science and Technology (HUST)
>>>
>>> Email: hoangthuong.hust at gmail.com
>>> Tel: +33 06 52 92 00 96
>>> Tel: +84 01692887738
>>>
>>>
>>> _______________________________________________
>>> AstroPy mailing list
>>> AstroPy at scipy.org
>>> http://mail.scipy.org/mailman/listinfo/astropy
>>>
>>>
>>
>>
>> --
>> Trey V. Wenger
>> Department of Astronomy
>> University of Virginia
>> http://www.astro.virginia.edu/~tvw2pu/
>>
>
>
>
> --
>
> ================================================
> THUONG Hoang Duc
>
> Université des Sciences et des Technologies de Hanoi(USTH)
> University of Science and Technology of Hanoi(USTH)
> Hanoi University of Science and Technology (HUST)
>
> Email: hoangthuong.hust at gmail.com
> Tel: +33 06 52 92 00 96
> Tel: +84 01692887738
>
>
--
Trey V. Wenger
Department of Astronomy
University of Virginia
http://www.astro.virginia.edu/~tvw2pu/
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