concatenate Numeric

Sheldon shejo284 at gmail.com
Mon Jul 10 05:58:22 EDT 2006


Robert Kern skrev:

> Sheldon wrote:
> > Thanks again for showing me this. I have been trying to read up on
> > reduce() as I have never used it before. I would like to know what it
> > does. So far my search has found nothing that I can grasp. The
> > reference library notes are estoteric at best.
> > Can you enlighten me on this matter?'
>
> The .reduce() method on ufuncs works pretty much like the reduce() builtin
> function. It applies the binary ufunc along the given axis of the array (the
> first one by default) cumulatively.
>
>    a = [3, 2, 1, 0]
>    minimum.reduce(a) == minimum(minimum(minimum(a[0], a[1]), a[2]), a[3])
>
> I will note, in the form of enticement to get you to try the currently active
> array package instead of Numeric, that in numpy, arrays have methods to do
> minimums and maximum rather more conveniently.
>
>  >>> import numpy as N
>  >>> a = N.rand(3, 5)
>  >>> a
> array([[ 0.49892358,  0.11931907,  0.37146848,  0.07494308,  0.91973863],
>         [ 0.92049698,  0.35016683,  0.01711571,  0.59542456,  0.49897077],
>         [ 0.57449315,  0.99592033,  0.20549262,  0.25135288,  0.04111402]])
>  >>> a.min()
> 0.017115711878847639
>  >>> a.min(axis=0)
> array([ 0.49892358,  0.11931907,  0.01711571,  0.07494308,  0.04111402])
>  >>> a.min(axis=1)
> array([ 0.07494308,  0.01711571,  0.04111402])
>
> --
> Robert Kern
>
> "I have come to believe that the whole world is an enigma, a harmless enigma
>   that is made terrible by our own mad attempt to interpret it as though it had
>   an underlying truth."
>    -- Umberto Eco

Thanks for the explanation! Super.
I am trying to get my bosses to purchase the Numpy documentation and
upgrade to Numpy as well as matplotlib and other necessary scientific
modules. But it is not entirely up to me. Still I need to learn more
about Python and installing these modules myself.




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