Sampling - xcist/documentation GitHub Wiki

There are a number of variables that can be used to adjust sampling, in order to reduce simulation time by sacrificing precision, or increase precision at the expense of simulation time. These are:

cfg.number_Ebins number of energy bins used for the spectrum (1=monochromatic, empty=use the number of energy bins used in the source spectrum file)
cfg.focal_oversample_x number of samples in the x-direction for the focal spot.
cfg.focal_oversample_y number of samples in the y-direction for the focal spot.
cgf.col_oversample number of samples in the column-direction for the detector cells.
cfg.row_oversample number of samples in the row-direction for the detector cells.
cfg.subviews_per_view number of sub-samples for each view (at different rotation increments). cfg.subviews_per_view=1 represents a pulsed X-ray source.

Note: In order to take full advantage of the focal spot and detector models, and correctly model spatial resolution, appropriate oversampling must be utilized. The required sampling depends on a number of factors, including focal spot specification (size and distribution), system geometry, phantom specification (feature size and location within the FOV), and detector specification (cell size and crosstalk). As a starting point, if simulating a 50 µm wire, the following oversampling is suggested.

cfg.focal_oversample_x = 10;   % vary in the range of 7-15 to evaluate
                               % dependency on this parameter.
cfg.focal_oversample_y = 1;
cgf.col_oversample = 30;       % vary in the range of 20-40 to evaluate
                               % dependency on this parameter.
cgf.col_oversample = 1;
cfg.subviews_per_view =  1;    % vary in the range of
                               %  1 for features at the center of the FOV,
                               % 10 for features at the edge of the FOV.

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