hyperspy._signals.dielectric_function module

class hyperspy._signals.dielectric_function.DielectricFunction(*args, **kwargs)

Bases: hyperspy._signals.dielectric_function.DielectricFunction_mixin, hyperspy._signals.complex_signal1d.ComplexSignal1D

class hyperspy._signals.dielectric_function.DielectricFunction_mixin

Bases: object

get_electron_energy_loss_spectrum(zlp, t)
get_number_of_effective_electrons(nat, cumulative=False)

Compute the number of effective electrons using the Bethe f-sum rule.

The Bethe f-sum rule gives rise to two definitions of the effective number (see [Egerton2011]), neff1 and neff2:

n_{\mathrm{eff_{1}}} = n_{\mathrm{eff}}\left(-\Im\left(\epsilon^{-1}\right)\right)


n_{\mathrm{eff_{2}}} = n_{\mathrm{eff}}\left(\epsilon_{2}\right)

This method computes and return both.

  • nat (float) – Number of atoms (or molecules) per unit volume of the sample.
  • cumulative (bool) – If False calculate the number of effective electrons up to the higher energy-loss of the spectrum. If True, calculate the number of effective electrons as a function of the energy-loss up to the higher energy-loss of the spectrum. True is only supported by SciPy newer than 0.13.2.

neff1, neff2 – Signal1D instances containing neff1 and neff2. The signal and navigation dimensions are the same as the current signal if cumulative is True, otherwise the signal dimension is 0 and the navigation dimension is the same as the current signal.

Return type:



[Egerton2011]Ray Egerton, “Electron Energy-Loss

Spectroscopy in the Electron Microscope”, Springer-Verlag, 2011.

class hyperspy._signals.dielectric_function.LazyDielectricFunction(*args, **kwargs)

Bases: hyperspy._signals.dielectric_function.DielectricFunction, hyperspy._signals.complex_signal1d.LazyComplexSignal1D