Hi Faheem,
In order to create an object array, do this:
>>> import numarary.objects as obj
>>> a = obj.fromlist(["t","u","w",1])
>>> a
ObjectArray(["t","u","w",1)
Unfortunately, the ability to apply arbitrary functions to all the elements
of an object array has never been implemented. Nevertheless, the following
might do:
def apply(array, function, result=None):
rank1 = (array.rank == 1)
if result is None:
result0 = array.copy()
else:
result0 = result
for x in range(array.shape[0]):
if rank1:
result0[x] = function(array[x])
else:
apply(array[x], function, result0[x])
return result0
Re-ordering the loop and the if statement results in faster but slightly
more verbose code.
Regards,
Todd Miller
----- Original Message -----
From: "Faheem Mitha" <fa...@em...>
To: <num...@li...>
Sent: Sunday, March 14, 2004 12:20 PM
Subject: [Numpy-discussion] Re: numarray.objects missing in documentation
> On Sun, 14 Mar 2004 09:55:52 -0500, Todd Miller <jm...@st...> wrote:
> > On Sun, 2004-03-14 at 00:26, Faheem Mitha wrote:
> >> Dear People,
> >>
> >> I'm posting this to gmane.comp.python.numeric.general. I am not sure
> >> what mailing list this corresponds to. I earlier tried to post this to
> >> the mailing list mentioned in the numarray documentation
> >> (nu...@li...), but it bounced.
> >>
> >> I don't see numarray.objects listed in
> >> http://stsdas.stsci.edu/numarray/numarray-0.9.html/genindex.html
> >
> > The section on object arrays has yet to be written. What is it that you
> > want to know?
>
> Thanks for the quick reply. I'm trying to make an array of python
> objects as follows. Specifically, given a user defined class, I want
> to creata an array of instances of that class.
>
> Consider the following class.
>
> class cell:
> def setrow(self,row):
> self.row = row
> def setcol(self,col):
> self.col = col
> ...
>
> I create an "empty" cell.
>
> empcell = cell()
>
> Now I want to create an array of objects identical to empcell, and
> later initialize them.
>
> I tried stuff along the lines of
>
> ******************************************************************
> import string
> from numarray import *
>
> empcell = cell()
>
> base = [empcell]
>
> mat = fromlist(base,shape=(2,2))
> ******************************************************************
>
> But the
>
> mat = fromlist(base,shape=(2,2))
>
> line fails with
>
> AttributeError: cell instance has no attribute '__len__'
>
> Similar things fail with the same error message. No doubt I'm doing
> something stupid, but would someone please enlighten me?
>
> I got the fromlist command from
>
> >>> help("numarray.objects")
>
> I was a bit disconcerted to find on trying to run the first example
> from the help page that I got
>
> >>> a = fromlist(["t","u","w"])
> ...
> TypeError: Expecting a python numeric type, got something else.
>
> What am I doing wrong?
>
> I'm running
>
> ii python 2.3.3-5 An interactive
> high-level object-oriented language (default versio
> ii python-numarray 0.8.1-1 An array
> processing package modelled after Python-Numeric
> ii python-numeric 23.1-1 Numerical
> (matrix-oriented) Mathematics for Python
>
> on Debian sarge.
>
> Thanks in advance and sorry for the long-winded message.
>
> Faheem.
>
>
>
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