fromfile error on windows, not mac

jadamwil jadamwilson2 at
Tue Jul 22 06:36:38 CEST 2008

I am using the numpy fromfile function to read binary data from a file
on disk. The problem is that the program runs fine on a Mac, but gives
an error or warning on windows when trying to read the data. I use it
like this:

Signal = zeros((N, 16), dtype=float32)
for sample in range(0, N):
  # this function gets the next position in the file to seek to
  s = getFilePos(sample)

  # go to the correct location in the file; this IS checked to make
sure it is within the file

  # read the 16 float32 values from the file
  D = fromfile(mFile, dtype=numpy.float32, 16)

  # save D in Signal
  Signal[sample, :] = D

This will fail when sample is ~4. If I change the range to (5,N),
skipping the "bad" file location, it will run fine for a few samples,
and then give another error. The message it gives is:
"16 items requested but only 7 read"

So D is a 7x1 vector, and the program dies when it tries to assign D
to the slice of Signal ("ValueError: shape mismatch: objects cannot be
broadcast to a single shape").

On windows, the Python version is 2.5.2, and the most recent numpy and
scipy are being used as well. I tried using Enthought, but it gave
this error as well, in addition to a c runtime error whenever I
imported scipy (which is another post topic...).

Any ideas on what might be causing this? Is there a way to debug the
fromfile function? And, remember, this works perfectly on a Mac. Would
compiling everything (python, scipy, numpy) potentially solve this?


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