numpy or _numpy or Numeric?

Travis E. Oliphant oliphant.travis at ieee.org
Wed Jan 24 09:02:17 CET 2007


auditory wrote:
> I am a newbie here
> 
> I am trying to read "space separated floating point data" from file
> 
> I read about csv module by searching this group,
> but I couldn't read space separated values with csv.
> (which may be matter of course..)
> 
> I also read about numpy.fromfile(file, sep=' ') which i can use.
> but on my machine(ubuntu linux) numpy is unknown module,
> which I didn't install by myself.

You will need to install NumPy.

> 
> While trying to install numpy accroding to its homepage.
> (http://numpy.scipy.org/numpydoc/numdoc.htm).
> i am quite confused.

You are reading old documentation for Numeric and so any installation 
description is how to install the Numeric module (not its newer 
replacement which is called NumPy).


So:

1) Yes, you need NumPy
2) This *is different* from Numeric
3) You get it by either installing a pre-built package for your system 
or by

    a) downloading the source tar-file from 
http://sourceforge.net/project/showfiles.php?group_id=1369&package_id=175103
      (get the numpy-<version>.tar.gz file
    b) tar zxvf numpy-<version>.tar.gz
    c) cd numpy-<version>
    d) sudo python setup.py install

    e) If you want to link against high-performance libraries on your 
system, then either put them in standard locations or edit the site.cfg 
file appropriately (Optional).

> 
> 4. Or what is general way to read 'space separated values' from file?

You can easily read space-separated values from a file by reading in a 
line at a time and using the split method of strings:

fid = open('filename')
linedata = fid.readlines()
new = [[float(x) for x in line.split()] for line in linedata]

new will be a nested sequence of floats.  You can convert it to an array 
(if you want to do math on it) using

anew = numpy.array(new)

-Travis




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