Package: python-numpy
Version: 1:1.0.4-5
Severity: normal
>>> x = numpy.array([[1,2,3,4,5,6,2],[2,2,3,4,5,6,3]]).transpose()
>>> wt = numpy.array([1,1,1,1,1,1,2])
>>> numpy.average(x, weights=wt, axis=0)
array([[[[[[ 1., 2.],
[ 2., 2.],
[ 3., 3.],
[ 4., 4.],
[ 5., 5.],
[ 6., 6.],
[ 2., 3.]]]]]])
So, the weighted average of a 2-dimentional array is a 6-dimensional
array?
Or, slightly better:
>>> x = numpy.array([range(100),range(100)]).transpose()
>>> wt = numpy.array(range(100))
>>> numpy.average(x, weights=wt, axis=0)
Traceback (most recent call last):
File "<stdin>", line 1, in ?
File
"/usr/local/lib/python2.4/site-packages/numpy-1.0.4-py2.4-linux-i686.egg/numpy/lib/function_base.py",
line 379, in average
w1 = eval("w["+repr(tuple(r))+"]*ones(ash, float)")
File "<string>", line 0, in ?
IndexError: too many indices
>>>
The problem seems to be in .../numpy/lib/function_base.py
right here:
if wsh == ():
wsh = (1,)
if wsh == ash:
n = add.reduce(a*w, axis)
d = add.reduce(w, axis)
elif wsh == (ash[axis],):
# ni = len(ash) #CORRECT!
ni = ash[axis] # WRONG!
r = [newaxis]*ni
r[axis] = slice(None, None, 1)
w1 = eval("w["+repr(tuple(r))+"]*ones(ash, float)")
n = add.reduce(a*w1, axis)
d = add.reduce(w1, axis)
else:
raise ValueError, 'averaging weights have wrong shape'
The existing code generates an array whose dimensionality is
equal to shape[axis], so it you have a 2-dimensional array
with a shape of (1000,3), it will try to generate a 1000-dimensional
array on the output.
And, Geez! Calling eval() in code that is supposed to be fast?
Yikes! (But that's a separate issue...)
-- System Information:
Debian Release: lenny/sid
APT prefers testing
APT policy: (500, 'testing')
Architecture: i386 (i686)
Kernel: Linux 2.6.22-3-686 (SMP w/1 CPU core)
Locale: LANG=en_GB, LC_CTYPE=en_GB (charmap=ISO-8859-1)
Shell: /bin/sh linked to /bin/bash
Versions of packages python-numpy depends on:
ii atlas3-base [liblapack 3.6.0-20.6 Automatically Tuned Linear Algebra
ii atlas3-sse2 [liblapack 3.6.0-20.6 Automatically Tuned Linear Algebra
ii lapack3 [liblapack.so. 3.0.20000531a-6.1 library of linear algebra routines
ii libc6 2.7-6 GNU C Library: Shared libraries
ii libg2c0 1:3.4.6-6 Runtime library for GNU Fortran 77
ii libgcc1 1:4.3-20080202-1 GCC support library
ii python 2.4.4-6 An interactive high-level object-o
ii python-support 0.7.6 automated rebuilding support for p
ii refblas3 [libblas.so.3 1.2-8 Basic Linear Algebra Subroutines 3
python-numpy recommends no packages.
-- no debconf information
--
To UNSUBSCRIBE, email to [EMAIL PROTECTED]
with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
