get_variance#

Diffraction2D.get_variance(npt, method='Omega', dqe=None, spatial=False, navigation_axes=None, **kwargs)[source]#

Calculates the variance using one of the methods described in [1]. A shot noise correction: and specification of axes to operate over are also possible.

Parameters:

npt (int) – The number of points to use in the azimuthal integration
method (‘Omega’ or ‘r’ or ‘re’ or ‘VImage’, optional) – The method used to calculate the variance. Details in [1]
dqe (int, optional) – The detector quantum efficiency or the pixel value for one electron.
spatial (bool, optional) – Included intermediate spatial variance in output (only available if method==’r’)
navigation_axes (list or none, optional) – The axes to calculate the variance over. The default is to use the navigation axes.
**kwargs (dict) – Any keywords accepted for the pyxem.signals.Diffraction2D.get_azimuthal_integral1d() or pyxem.signals.Diffraction2D.get_azimuthal_integral2d() function

Returns:

variance – Calculate variance as it’s own signal

Return type:

array-like

References

[1] Daulton, T. L et al, Ultramicroscopy, 110(10), 1279–1289, https://doi.org/10.1016/j.ultramic.2010.05.010: Nanobeam diffraction fluctuation electron microscopy technique for structural characterization of disordered materials-Application to Al88-xY7Fe5Tix metallic glasses.