inverse method not working for any filter about pygsp HOT 4 OPEN

Hi, thanks for your interest! You may be using an older version. Try to install the latest from github with pip install git+https://github.com/epfl-lts2/pygsp. (Discussion in #69.)

from pygsp.

I'm on the latest version and also facing the same issue.

I'm also a little confused with the way the package works. If I understand correctly, given a wavelet filter g, g.filter(signal) should give the wavelet coefficients c, and g.inverse(c) should reconstruct the signal, right?

from pygsp.

To inverse coefficient, you have to use the synthesize function. Synthesis is actually the inverse of analysis (analyze is actually the same as filter). The inverse function returns another filter, and does not inverse the coefficients.

Here is untested pseudo code:

signal = np.random.randn(G.N,1)
inverse_filter = g.inverse()
coefs = g.analyze(signal)
reconstructed_signal = inverse_filter.synthesize(coefs)
np.linalg.norm(reconstructed_signal-signal)

Good luck

from pygsp.

Thanks for the pseudo-code and the explanation! The problem still remains in calculating in inverse filter though, since it gives the "object has no attribute 'inverse' " error. Is there a workaround for this?

from pygsp.