[Numpy-discussion] gradient with memmap array bug (?)

Fred fredmfp@gmail....
Mon Sep 5 05:43:34 CDT 2011


Hi all,

I get some issue using gradient on an array created from memmap:

PC-Fred[pts/10]:~/{11}/> ipython -p numpy
Python 2.6.7 (r267:88850, Jul 10 2011, 08:11:54)
Type "copyright", "credits" or "license" for more information.

IPython 0.10.2 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object'. ?object also works, ?? prints more.

IPython profile: numpy

PC-Fred[12:39:18]:~/{1}/> a=array([[1.,2.], [3., 4.]], dtype='f')

PC-Fred[12:40:24]:~/{2}/> a.tofile('a.sep')

PC-Fred[12:40:32]:~/{3}/> del a

PC-Fred[12:40:45]:~/{4}/> a = memmap('a.sep', mode='r', dtype='f', 
shape=(2,2))

PC-Fred[12:40:49]:~/{5}/> x, y = gradient(a, 1, 1)
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)

/mnt/common/home/fred/<ipython console> in <module>()

/usr/lib/pymodules/python2.6/numpy/lib/function_base.py in gradient(f, 
*varargs)
     842     for axis in range(N):
     843         # select out appropriate parts for this dimension

--> 844         out = np.zeros_like(f).astype(otype)
     845         slice1[axis] = slice(1, -1)
     846         slice2[axis] = slice(2, None)

/usr/lib/pymodules/python2.6/numpy/core/memmap.py in 
__array_finalize__(self, obj)
     255         if hasattr(obj, '_mmap'):
     256             self._mmap = obj._mmap
--> 257             self.filename = obj.filename
     258             self.offset = obj.offset
     259             self.mode = obj.mode

AttributeError: 'memmap' object has no attribute 'filename'


Sounds like a bug or not?

Any clue?

TIA.

Cheers,



PS : NumPy 1.5.1 on wheezy debian box

-- 
Fred


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