[SciPy-User] Asymmetric peak fitting

[jkhilmer at chemistry.montana.edu]

>
>
> Ah, sorry the very poor memory.  There was a fix to the expgaussian()
> function a month ago, after the 0.8.3 release (and thanks to Tim Spillane
> for the fix!).    That explains the problem you're seeing, and might
> explain why Pawel was having trouble too.   The fix is fairly simple
> (change `arg2` to have `/(s2*sigma)` instead of `/s`,  see
> https://github.com/lmfit/lmfit-py/blob/master/lmfit/lineshapes.py#L116),
> and should be orthogonal to any other changes in the current branch.
>
>
Thanks for checking into this.  Do you have any thoughts on the analysis by
Kalambet and Tikhonov in the paper I linked previously?  Specifically, in
the code:

gss = gamma*sigma*sigma
arg1 = gamma*(center +gss/2.0 - x)
arg2 = (center + gss - x)/(s2*sigma)
return amplitude*(gamma/2) * exp(arg1) * erfc(arg2)

The exp(arg1) factor is much too large and erfc(arg2) is much too small,
when x<1/gamma ?


Jonathan
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