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| From | Peter Otten <__peter__@web.de> |
| Newsgroups | comp.lang.python |
| Subject | Re: 4D arrays |
| Date | Tue, 01 Dec 2015 18:47:09 +0100 |
| Organization | None |
| Lines | 56 |
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jorge.conrado@cptec.inpe.br wrote:
> I use the IDL but now I'm change to PYTHON. I have a 4D array (time,
> level,lon,lat). I would like to get a 2D array for a specific time
> (time1) and level (level1). In IDL I use: 2Darray =
> 4Darray(time1,level1,*,*). How can I get the 2D array in Python
With numpy you can use slicing.
Create a 4D array with pointless data in it:
>>> import numpy
>>> a = numpy.arange(2*3*4*5).reshape((2, 3, 4, 5))
>>> a
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]],
[[ 40, 41, 42, 43, 44],
[ 45, 46, 47, 48, 49],
[ 50, 51, 52, 53, 54],
[ 55, 56, 57, 58, 59]]],
[[[ 60, 61, 62, 63, 64],
[ 65, 66, 67, 68, 69],
[ 70, 71, 72, 73, 74],
[ 75, 76, 77, 78, 79]],
[[ 80, 81, 82, 83, 84],
[ 85, 86, 87, 88, 89],
[ 90, 91, 92, 93, 94],
[ 95, 96, 97, 98, 99]],
[[100, 101, 102, 103, 104],
[105, 106, 107, 108, 109],
[110, 111, 112, 113, 114],
[115, 116, 117, 118, 119]]]])
Extract 2D arrays:
>>> a[:,2,3]
array([[ 55, 56, 57, 58, 59],
[115, 116, 117, 118, 119]])
>>> a[1,:,2]
array([[ 70, 71, 72, 73, 74],
[ 90, 91, 92, 93, 94],
[110, 111, 112, 113, 114]])
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Re: 4D arrays Peter Otten <__peter__@web.de> - 2015-12-01 18:47 +0100
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