Hi,
Thanks everybody for all the answers that make perfect sense when axis=0.
Now suppose I want to sort the array in such a way that each row is
sorted individually. Then I suppose I should do this:
from numpy import *
v = array([[4,3],
[1,12],
[23,7],
[11,6],
[8,9]])
idx = argsort(v, axis=1)
idx is then
[[1 0]
[0 1]
[1 0]
[1 0]
[0 1]]
which makes sense, since these are the indices in an order that would
sort each row. But when I try
a[idx, variuos_additional_arguments]
I just get strange results. Anybody that can point me towards the
correct solution.
Best regards,
Mads
On 01/15/2013 09:53 PM, eat wrote:
Hi,
On Tue, Jan 15, 2013 at 1:50 PM, Mads Ipsen <madsip...@gmail.com
<mailto:madsip...@gmail.com>> wrote:
Hi,
I simply can't understand this. I'm trying to use argsort to
produce indices that can be used to sort an array:
from numpy import *
indices = array([[4,3],[1,12],[23,7],[11,6],[8,9]])
args = argsort(indices, axis=0)
print indices[args]
gives:
[[[ 1 12]
[ 4 3]]
[[ 4 3]
[11 6]]
[[ 8 9]
[23 7]]
[[11 6]
[ 8 9]]
[[23 7]
[ 1 12]]]
I thought this should produce a sorted version of the indices array.
Any help is appreciated.
Perhaps these three different point of views will help you a little
bit more to move on:
In []: x
Out[]:
array([[ 4, 3],
[ 1, 12],
[23, 7],
[11, 6],
[ 8, 9]])
In []: ind= x.argsort(axis= 0)
In []: ind
Out[]:
array([[1, 0],
[0, 3],
[4, 2],
[3, 4],
[2, 1]])
In []: x[ind[:, 0]]
Out[]:
array([[ 1, 12],
[ 4, 3],
[ 8, 9],
[11, 6],
[23, 7]])
In []: x[ind[:, 1]]
Out[]:
array([[ 4, 3],
[11, 6],
[23, 7],
[ 8, 9],
[ 1, 12]])
In []: x[ind, [0, 1]]
Out[]:
array([[ 1, 3],
[ 4, 6],
[ 8, 7],
[11, 9],
[23, 12]])
-eat
Best regards,
Mads
--
+-----------------------------------------------------+
| Mads Ipsen |
+----------------------+------------------------------+
| Gåsebæksvej 7, 4. tv | |
| DK-2500 Valby | phone:+45-29716388 <tel:%2B45-29716388> |
| Denmark | email:mads.ip...@gmail.com
<mailto:mads.ip...@gmail.com> |
+----------------------+------------------------------+
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_______________________________________________
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--
+-----------------------------------------------------+
| Mads Ipsen |
+----------------------+------------------------------+
| Gåsebæksvej 7, 4. tv | |
| DK-2500 Valby | phone: +45-29716388 |
| Denmark | email: mads.ip...@gmail.com |
+----------------------+------------------------------+
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