[Numpy-discussion] numpy.correlate with phase offset 1D data series
Tue Mar 4 13:10:54 CST 2008
At 03:28 PM 3/3/2008, Ann wrote:
> >Sounds familiar. If you have a good signal-to-noise ratio, you can get
> >subpixel accuracy by oversampling the irfft, or better but slower, by
> >using numerical optimization to refine the peak you found with argmax.
the S/N here is poor, and high data rates work against me too...
> I would be inclined to use convolve (or scipy.ndimage.convolve, which
> uses a Fourier-domain method), since it is somewhat better specified.
I'll give it a try as well.
I'm guessing scipy.ndimage.correlate1d is a Fourier method too?
> From: "Timothy Hochberg" <email@example.com>
> I'm going to guess that you are using some flavor of Unix, since I also
> downloaded using Firefox and the data ends up corrupted. My hypothesis is
> that Firefox doesn't recognize the mime type and treats it as a text file,
> corrupting it on Windows, but not on Unix. Then again, maybe you're not
> using Unix and my installation of Firefox is just broken.
I think that is the case, I have Win2K on this box
> With the CSV version I do get a peak at the (un)expected location (7489//2).
> The peak is pretty flat and only twice the size of the surrounding gunk, but
> it looks more or less legit.
I don't see that in my pylab plot! There's actually a dip, and the
whole plot is symmetric about 3744
http://rjs.org/Python/corr_array.jpg, self xcorr of
I'll be upgrading my install here shortly though to py2.5 and associated libs.
My compiler/distutils environment is broken.
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