fill in 3D array
Robert Kern
robert.kern at gmail.com
Wed Jul 23 21:18:32 EDT 2008
knielsen73 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
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