improver.cli.field_texture module
Script to calculate whether or not the input field texture exceeds a given threshold.
- process(cube, *, nbhood_radius=20000.0, textural_threshold=0.05, diagnostic_threshold=0.8125, model_id_attr=None)[source]
Calculates field texture for a given neighbourhood radius.
The field texture is an assessment of the transitions/edges within a neighbourhood of a grid point to indicate whether the field is rough or smooth.
- Parameters:
cube (iris.cube.Cube) – The diagnostic for which texture is to be assessed. For example cloud area fraction where transitions between cloudy regions and cloudless regions will be diagnosed. Defaults set assuming cloud area fraction cube.
nbhood_radius (float) – The neighbourhood radius in metres within which the number of potential transitions should be calculated. This forms the denominator in the calculation of the ratio of actual to potential transitions that indicates a field’s texture. A larger radius should be used for diagnosing larger-scale textural features. Default value set to 10000.0 assuming cloud area fraction cube.
textural_threshold (float) – A unit-less threshold value that defines the ratio value above which the field is considered rough and below which the field is considered smoother. Default value set to 0.05 assuming cloud area fraction cube.
diagnostic_threshold (float) – The diagnostic threshold for which field texture will be calculated. A ValueError is raised if this threshold is not present on the input cube. Default value set to 0.8125 corresponding to 6 oktas, assuming cloud area fraction cube.
model_id_attr (str) – Name of the attribute used to identify the source model for blending.
- Returns:
A field texture cube containing values between 0 and 1, where 0 indicates no transitions and 1 indicates the maximum number of possible transitions has been achieved, within the neighbourhood of the grid point.
- Return type: