L1_poly = CaputoL1point(-0.5, lambda x: x**2 - 1)

[creator2020A]

Your example here in the website:
L1_poly = CaputoL1point(-0.5, lambda x: x**2 - 1)
Gives an error from your code def CaputoL1point
if alpha <= 0 or alpha >= 1:
raise ValueError('Alpha must be in (0, 1) for this method.')
May I ask what am I missing?

[cooperhatfield]

The alpha value refers to the level of differentiation, you're specifying alpha=-0.5 which is a half integration. If that's what you want to do, you should first integrate your function normally, and then take a half derivative by specifying alpha=0.5.

I'll update that example to fix the error, thank you for noticing!

[creator2020A]

Hi Differint/Differint, But in your example code it works exactly like that?

…

On Tue, Feb 13, 2024 at 12:24 PM Cooper Hatfield ***@***.***> wrote: The alpha value refers to the level of differentiation, you're specifying alpha=-0.5 which is a half integration. If that's what you want to do, you should first integrate your function normally, and then take a half derivative by specifying alpha=0.5. — Reply to this email directly, view it on GitHub <#25 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ARKYELMOWKQM4RDDJC5NRITYTKQD7AVCNFSM6AAAAABDFPVBVWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTSMZZG43TINBZGU> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[creator2020A]

Hi Differint/Differint, Sorry to keep asking, I don't have the reference book. So May I ask if your fractional derivative in Caputo sense is the same as the wikipedia page https://en.wikipedia.org/wiki/Fractional_calculus? On Tue, Feb 13, 2024 at 1:27 PM Ranjan Acharyya ***@***.***> wrote:

…

Hi Differint/Differint, But in your example code it works exactly like that? On Tue, Feb 13, 2024 at 12:24 PM Cooper Hatfield ***@***.***> wrote: > The alpha value refers to the level of differentiation, you're specifying > alpha=-0.5 which is a half integration. If that's what you want to do, > you should first integrate your function normally, and then take a half > derivative by specifying alpha=0.5. > > — > Reply to this email directly, view it on GitHub > <#25 (comment)>, > or unsubscribe > <https://github.com/notifications/unsubscribe-auth/ARKYELMOWKQM4RDDJC5NRITYTKQD7AVCNFSM6AAAAABDFPVBVWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTSMZZG43TINBZGU> > . > You are receiving this because you authored the thread.Message ID: > ***@***.***> >

[cooperhatfield]

Hi Differint/Differint, But in your example code it works exactly like that?
…
On Tue, Feb 13, 2024 at 12:24 PM Cooper Hatfield @.> wrote: The alpha value refers to the level of differentiation, you're specifying alpha=-0.5 which is a half integration. If that's what you want to do, you should first integrate your function normally, and then take a half derivative by specifying alpha=0.5. — Reply to this email directly, view it on GitHub <#25 (comment)>, or unsubscribe https://github.com/notifications/unsubscribe-auth/ARKYELMOWKQM4RDDJC5NRITYTKQD7AVCNFSM6AAAAABDFPVBVWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTSMZZG43TINBZGU . You are receiving this because you authored the thread.Message ID: @.>

I believe the wiki page was written using an old implementation, but it was written so long ago that I don't know why there's an example giving a result with an invalid call of the function.

[creator2020A]

Thank you.

[cooperhatfield]

It should work the same way as the theoretical formula, ignoring issues/errors due to the algorithm. For specifics, you should be able to find a reference to the paper used for the implementation in the functions docstring.