Analytical value and partial derivatives of the dispersive lorentzian function centered at x=0.
position at which to evaluate.
full width at half maximum.
the value fct and its partial derivatives with respect to x (dx) and fwhm (dFwhm).
fct
x
dx
fwhm
dFwhm
Analytical value and partial derivatives of the dispersive lorentzian function centered at x=0.