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mbagagli / filterpicker

general purpose, broad-band, seismic-phase detector and picker
MIT License
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In calculation of yLP value... #2

Open jinguman opened 9 months ago

jinguman commented 9 months ago

Hello First of all, thanks you for the source. It helped me for reading the paper(A. Lomax, 2012).

But I have the question. In the eq(5) of the paper, Yn_LP(i) = Yn_LP(i-1)+Cn_LP[Y_HP2(i) - Y_HP2(i-1)] And In your code,
yLP = yLPp + cLP*(yHP2 - yLPp)

According to the paper, it should look like this yLP = yLPp + cLP*(yHP2 - yHP2p )

I wonder which one is right.

Regards.

mbagagli commented 9 months ago

Dear @jinguman thanks for pointing this out. Indeed there's a discrepancy among the 2 equations.

After cross-checking with the original authors (Anthony Lomax) and their C source code, it turned out that the one reported in the code is the correct one (not the one reported in the paper). The Low-Pass filtering iteration has also been taken from here: http://en.wikipedia.org/wiki/Low-pass_filter

Thanks for letting me know. I'll leave the issue open so others may as well see it.