indexing question

[Faheem Mitha]

Dear People,

Suppose I create a numarray arry (say). A numeric array would be fine
too; it probably does not matter.
[color=blue][color=green][color=darkred]
>>>import numarray
>>>foo = numarray.reshap e(numarray.aran ge(9),(3,3))[/color][/color][/color]
array([[ 0, 1, 2, 3],
[ 4, 5, 6, 7],
[ 8, 9, 10, 11],
[12, 13, 14, 15]])

Is there some way to select the indexes corresponding only to (say)
two rows or columns?

ie suppose I just want the first and the fourth row or the first and
third columns? Is there some clean way to do this which does not
involve extract individual rows or columns?

Ie. I want something like[color=blue][color=green][color=darkred]
>>> foo[?,:][/color][/color][/color]
array([[ 0, 1, 2, 3],
[12, 13, 14, 15]])

etc.

Suggestions appreciated. Thanks in advance.

Faheem.

[wes weston]

Re: indexing question

Faheem Mitha wrote:[color=blue]
> Dear People,
>
> Suppose I create a numarray arry (say). A numeric array would be fine
> too; it probably does not matter.
>
>[color=green][color=darkred]
>>>>import numarray
>>>>foo = numarray.reshap e(numarray.aran ge(9),(3,3))[/color][/color]
>
> array([[ 0, 1, 2, 3],
> [ 4, 5, 6, 7],
> [ 8, 9, 10, 11],
> [12, 13, 14, 15]])
>
> Is there some way to select the indexes corresponding only to (say)
> two rows or columns?
>
> ie suppose I just want the first and the fourth row or the first and
> third columns? Is there some clean way to do this which does not
> involve extract individual rows or columns?
>
> Ie. I want something like
>[color=green][color=darkred]
>>>>foo[?,:][/color][/color]
>
> array([[ 0, 1, 2, 3],
> [12, 13, 14, 15]])
>
> etc.
>
> Suggestions appreciated. Thanks in advance.
>
> Faheem.[/color]

Faheem,
On the following like, I see something like what you
want.

http://matpy.sourceforge.net/MatPy/node3.html

wes

[Faheem Mitha]

Re: indexing question

On Fri, 26 Mar 2004 16:32:32 GMT, wes weston <wweston@att.ne t> wrote:
[color=blue]
> Faheem,
> On the following like, I see something like what you
> want.
>
> http://matpy.sourceforge.net/MatPy/node3.html[/color]

Yes, I realise that I can take slices as long as the corresponding
rows and columns are contiguous. My question is, how can I make a
subarray from rows or columns that are *not* contiguous? If this is
possible, can you show me an example?

Faheem.