[Numpy-discussion] reshape 2D array into 3D

[paul.carrico at free.fr]

Thanks 

Nevertheless it does not work for me and I suspect the python/numpy
releases :-( 

The server on which I'm working on is under Contos 7 that uses python
2.7 et numpy 1.7 from memory ; I tried to upgrade both of them (plus
spyder) but it fails. 

I didn't want to impact the other solvers installed on, so I stopped 

Paul 

a = np.arange(40).reshape(5, 8); print(a)
print("b =")
b = np.lib.stride_tricks.as_strided(a, (2, 5, 4), (16, 32, 4)); print(b)


[[ 0 1 2 3 4 5 6 7]
[ 8 9 10 11 12 13 14 15]
[16 17 18 19 20 21 22 23]
[24 25 26 27 28 29 30 31]
[32 33 34 35 36 37 38 39]]
b =
[[[ 0 4294967296 1 8589934592]
[ 4 21474836480 5 25769803776]
[ 8 38654705664 9 42949672960]
[ 12 55834574848 13 60129542144]
[ 16 73014444032 17 77309411328]] 

[[ 2 12884901888 3 17179869184]
[ 6 30064771072 7 34359738368]
[ 10 47244640256 11 51539607552]
[ 14 64424509440 15 68719476736]
[ 18 81604378624 19 85899345920]]] 

Le 2017-07-10 15:16, eat a écrit :

> Hi, 
> 
> On Mon, Jul 10, 2017 at 3:20 PM, <paul.carrico at free.fr> wrote:
> 
>> Dear All 
>> 
>> I'm looking in a way to reshape a 2D matrix into a 3D one ; in my example I want to MOVE THE COLUMNS FROM THE 4TH TO THE 8TH IN THE 2ND PLANE  (3rd dimension i guess) 
>> 
>> a =  np.random.rand(5,8); print(a) 
>> 
>> I tried 
>> 
>> a = p.reshape(d, (2,5,4), ) but it is not what I'm expecting 
>> 
>> Nota : it looks like the following task (while I want to split it in 2 levels and not in 4), but I've not understood at all 
>> 
>> https://stackoverflow.com/questions/31686989/numpy-reshape-and-partition-2d-array-to-3d [1]
> 
> Is this what you are looking for:  
> 
> import numpy as np 
> 
> a= np.arange(40).reshape(5, 8) 
> 
> a 
> Out[]:  
> array([[ 0,  1,  2,  3,  4,  5,  6,  7], 
> [ 8,  9, 10, 11, 12, 13, 14, 15], 
> [16, 17, 18, 19, 20, 21, 22, 23], 
> [24, 25, 26, 27, 28, 29, 30, 31], 
> [32, 33, 34, 35, 36, 37, 38, 39]]) 
> 
> np.lib.stride_tricks.as_strided(a, (2, 5, 4), (16, 32, 4)) 
> Out[]:  
> array([[[ 0,  1,  2,  3], 
> [ 8,  9, 10, 11], 
> [16, 17, 18, 19], 
> [24, 25, 26, 27], 
> [32, 33, 34, 35]], 
> 
> [[ 4,  5,  6,  7], 
> [12, 13, 14, 15], 
> [20, 21, 22, 23], 
> [28, 29, 30, 31], 
> [36, 37, 38, 39]]]) 
> 
> Regards, 
> -eat 
> 
>> Thanks for your support 
>> 
>> Paul 
>> _______________________________________________
>> NumPy-Discussion mailing list
>> NumPy-Discussion at python.org
>> https://mail.python.org/mailman/listinfo/numpy-discussion [2]
> 
> _______________________________________________
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Links:
------
[1]
https://stackoverflow.com/questions/31686989/numpy-reshape-and-partition-2d-array-to-3d
[2] https://mail.python.org/mailman/listinfo/numpy-discussion
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