cctbx.xray.weighting_schemes module

class cctbx.xray.weighting_schemes.amplitude_unit_weighting

Bases: object

Mere unit weights for F

compute()

class cctbx.xray.weighting_schemes.intensity_quasi_unit_weighting(n_sigma=1.0)

Bases: object

Quasi-unit weights 1/(4 Fo^2) for F^2.

The weights are replaced by 1/(4 sigma(Fo^2)^2) for weak Fo^2, which are defined as Fo^2 < n_sigma * sigma(Fo^2)

compute()

class cctbx.xray.weighting_schemes.pure_statistical_weighting

Bases: object

1/sigma^2 weights

compute()

class cctbx.xray.weighting_schemes.shelx_weighting(a=0.1, b=0, c=0, d=0, e=0, f=0.3333333333333333, wavelength=None)

Bases: object

As the WGHT instruction in ShelXL

property calculated

compute(f_calc, scale_factor=None)

property observed

class cctbx.xray.weighting_schemes.simple_shelx_weighting(a=0.1, b=0)

Bases: object

As the WGHT instruction in ShelXL with only a and b terms. The implementation is straightforward without any attempt to save space or time: mostly a reference for tests.

compute(f_calc, scale_factor=None)