hess_fwhm_eta

TRXASprefitpack.mathfun.hess_fwhm_eta(fwhm_G: float, fwhm_L: float) → Tuple[ndarray, ndarray]

Calculate hessian of fwhm and eta of pseudo voigt profile with fwhm_G, fwhm_L based on Journal of Applied Crystallography. 33 (6): 1311–1316.

Parameters:

• fwhm_G – full width at half maximum of gaussian part

• fwhm_L – full width at half maximum of lorenzian part

Returns:

hessian of fwhm(fwhm_G, fwhm_L) and hessian of eta(fwhm_G, fwhm_L)

Note

1st column: d^2 f / d(fwhm_G)^2 2nd column: d^2 f / d(fwhm_G)d(fwhm_L) 3rd column: d^2 f / d(fwhm_L)^2