fill in 3D array

[knielsen73 at gmail.com]

On Jul 23, 9:18 pm, Robert Kern <robert.k... at gmail.com> wrote:
> knielse... at gmail.com wrote:
> > Hi,
>
> > I am a python newbie, trying to convert my IDL scripts to python. I am
> > kind of stuck at the moment. I am reading in a 1-D data file with 2000
> > data points. I need to put them in a 3-D array with size [10,10,20]. I
> > have defined the field array as arr = zeros((10,10,20)) but don't know
> > how to read the data into the array.
>
> I assume that you are using numpy. Use numpy.fromfile() and the .reshape()
> method. Assuming that your file is ASCII with numbers separated by whitespace:
>
>    import numpy
>    arr = numpy.fromfile(thefilename, sep=' ').reshape((10,10,20))
>
> There is no need, in this case, to create an array before reading the data.
>
> > Also, I need to extract a slice of a 3-D array and tried a =
> > array_name(:,:,20) but that didn't work.
>
> Python uses [] brackets for indexing, not ().
>
>    arr[:,:,20]
>
> --
> 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, working like a charm.