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Bibtex #17

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JulienSiems opened this issue Dec 16, 2021 · 4 comments
Open

Bibtex #17

JulienSiems opened this issue Dec 16, 2021 · 4 comments

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@JulienSiems
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I am using your code and it would be good to able to cite your repo!
Could you post how you'd like it to be cited?

Thanks for your great work!

@josemiotto
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josemiotto commented Dec 19, 2021 via email

@JulienSiems
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JulienSiems commented Dec 19, 2021

Hi José,

Great, no rush! Let me know once you have updated it.
I am pretty surprised how well fitting a stable distribution via your tabulated values works.
I compared against a more classical estimator for the tail index for samples of a stable distribution with different tail indices and skewness and your estimator was an order of magnitude more accurate in terms of mean absolute error.

I did notice some outliers in the estimation, though. It may help to implement retries for the optimization in scipy or use evolutionary algorithm, like differential evolution, rather than gradient-based optimization?

Best,
Julien

@josemiotto
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josemiotto commented Dec 19, 2021 via email

@JulienSiems
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JulienSiems commented Dec 19, 2021

Hi José,

but the classic problem there is to choose a boundary for the tail.

Do you mean to find the tail index by fitting an exponential decay to the tails?

I am using this one: https://link.springer.com/article/10.1007/s00184-014-0515-7 (Corollary 2.4)
It's for example used quite extensively in: https://arxiv.org/abs/1901.06053
Below, is the plot I meant for the absolute alpha estimation error for different stable samples.

image

Best,

Julien

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