Bug in freqz returning angular frequency and frequency response in backward order
The freqz function appears to return the frequency values and the frequency response backwards. Like it is supposed to return in the order (h,w) but it actually returns in the order (w,h). This can even be seen in the documentation here: http://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.freqz.html
On Wed, Aug 29, 2012 at 12:20 AM, Jeffrey Spencer <jeffspencerd@gmail.com>wrote:
The freqz function appears to return the frequency values and the frequency response backwards. Like it is supposed to return in the order (h,w) but it actually returns in the order (w,h).
This can even be seen in the documentation here: http://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.freqz.html
Jeff, freqz and freqs both return (w, h), which is correct. The mistake is in the example in the docstring for freqz. The line:
h, w = signal.freqz(b)
should be
w, h = signal.freqz(b)
Warren
_______________________________________________ SciPy-User mailing list SciPy-User@scipy.org http://mail.scipy.org/mailman/listinfo/scipy-user
K, that makes sense. Knew it had to be backwards somewhere. On Aug 29, 2012 8:36 PM, "Warren Weckesser" <warren.weckesser@enthought.com> wrote:
On Wed, Aug 29, 2012 at 12:20 AM, Jeffrey Spencer <jeffspencerd@gmail.com>wrote:
The freqz function appears to return the frequency values and the frequency response backwards. Like it is supposed to return in the order (h,w) but it actually returns in the order (w,h).
This can even be seen in the documentation here:
http://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.freqz.html
Jeff,
freqz and freqs both return (w, h), which is correct.
The mistake is in the example in the docstring for freqz. The line:
h, w = signal.freqz(b)
should be
w, h = signal.freqz(b)
Warren
_______________________________________________ SciPy-User mailing list SciPy-User@scipy.org http://mail.scipy.org/mailman/listinfo/scipy-user
_______________________________________________ SciPy-User mailing list SciPy-User@scipy.org http://mail.scipy.org/mailman/listinfo/scipy-user
On Wed, Aug 29, 2012 at 6:48 AM, Jeffrey Spencer <jeffspencerd@gmail.com>wrote:
K, that makes sense. Knew it had to be backwards somewhere. On Aug 29, 2012 8:36 PM, "Warren Weckesser" < warren.weckesser@enthought.com> wrote:
On Wed, Aug 29, 2012 at 12:20 AM, Jeffrey Spencer <jeffspencerd@gmail.com
wrote:
The freqz function appears to return the frequency values and the frequency response backwards. Like it is supposed to return in the order (h,w) but it actually returns in the order (w,h).
This can even be seen in the documentation here:
http://docs.scipy.org/doc/scipy/reference/generated/scipy.signal.freqz.html
Jeff,
freqz and freqs both return (w, h), which is correct.
The mistake is in the example in the docstring for freqz. The line:
h, w = signal.freqz(b)
should be
w, h = signal.freqz(b)
Pull request to fix this and add an example to signal.freqs is here: https://github.com/scipy/scipy/pull/299 Warren
Warren
_______________________________________________ SciPy-User mailing list SciPy-User@scipy.org http://mail.scipy.org/mailman/listinfo/scipy-user
_______________________________________________ SciPy-User mailing list SciPy-User@scipy.org http://mail.scipy.org/mailman/listinfo/scipy-user
_______________________________________________ SciPy-User mailing list SciPy-User@scipy.org http://mail.scipy.org/mailman/listinfo/scipy-user
participants (2)
-
Jeffrey Spencer -
Warren Weckesser