[Numpy-discussion] 1.1.1rc1 to be tagged tonight

[Ryan May]

Jarrod Millman wrote:
> Hello,
> 
> This is a reminder that 1.1.1rc1 will be tagged tonight.  Chuck is
> planning to spend some time today fixing a few final bugs on the 1.1.x
> branch.  If anyone else is planning to commit anything to the 1.1.x
> branch today, please let me know immediately.  Obviously now is not
> the time to commit anything to the branch that could break anything,
> so please be extremely careful if you have to touch the branch.
> 
> Once the release is tagged, Chris and David will create binary
> installers for both Windows and Mac.  Hopefully, this will give us an
> opportunity to have much more widespread testing before releasing
> 1.1.1 final at the end of the month.
> 
Can I get anyone to look at this patch for loadtext()?

I was trying to use loadtxt() today to read in some text data, and I had
a problem when I specified a dtype that only contained as many elements
as in columns in usecols.  The example below shows the problem:

import numpy as np
import StringIO
data = '''STID RELH TAIR
JOE 70.1 25.3
BOB 60.5 27.9
'''
f = StringIO.StringIO(data)
names = ['stid', 'temp']
dtypes = ['S4', 'f8']
arr = np.loadtxt(f, usecols=(0,2),dtype=zip(names,dtypes), skiprows=1)

With current 1.1 (and SVN head), this yields:

IndexError                                Traceback (most recent call last)

/home/rmay/<ipython console> in <module>()

/usr/lib64/python2.5/site-packages/numpy/lib/io.pyc in loadtxt(fname,
dtype, comments, delimiter, converters, skiprows, usecols, unpack)
     309                             for j in xrange(len(vals))]
     310         if usecols is not None:
--> 311             row = [converterseq[j](vals[j]) for j in usecols]
     312         else:
     313             row = [converterseq[j](val) for j,val in
enumerate(vals)]

IndexError: list index out of range
-----------------------------------------

I've added a patch that checks for usecols, and if present, correctly
creates the converters dictionary to map each specified column with
converter for the corresponding field in the dtype. With the attached
patch, this works fine:

 >arr
array([('JOE', 25.300000000000001), ('BOB', 27.899999999999999)],
       dtype=[('stid', '|S4'), ('temp', '<f8')])


Thanks,
Ryan

-- 
Ryan May
Graduate Research Assistant
School of Meteorology
University of Oklahoma

-- 
Ryan May
Graduate Research Assistant
School of Meteorology
University of Oklahoma
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