improver.cli.enforce_consistent_forecasts module

CLI to enforce consistency between two forecasts.

process(*cubes, ref_name=None, additive_amount=[0.0], multiplicative_amount=[1.0], comparison_operator=['>='], diff_for_warning=None)[source]

Module to enforce that the values in the forecast cube are not less than, not greater than, or between some linear function(s) of the corresponding values in the reference forecast.

Parameters:

  • cubes (iris.cube.CubeList or list of iris.cube.Cube) –

    containing:
    forecast_cube (iris.cube.Cube):

    Cube of forecasts to be updated by using the reference forecast to create a bound on the value of the forecasts.

    ref_forecast (iris.cube.Cube)

    Cube of forecasts used to create a bound for the values in forecast_cube. It must be the same shape as forecast_cube but have a different name.

  • ref_name (str) – Name of ref_forecast cube

  • additive_amount (List[float]) – The amount to be added to the reference forecast (in the units of the reference forecast) prior to enforcing consistency between the forecast and reference forecast. If both an additive_amount and multiplicative_amount are specified then addition occurs after multiplication. If a list is provided, then it must contain two float elements; one for defining the lower bound and one the upper.This option cannot be used for probability forecasts, if it is then an error will be raised.

  • multiplicative_amount (List[float]) – The amount to multiply the reference forecast by prior to enforcing consistency between the forecast and reference forecast. If both an additive_amount and multiplicative_amount are specified then addition occurs after multiplication. If a list is provided, then it must contain two float elements; one for defining the lower bound and one the upper.This option cannot be used for probability forecasts, if it is then an error will be raised.

  • comparison_operator (List[str]) – Determines whether the forecast is enforced to be not less than or not greater than the reference forecast. Valid choices for enforcing one bound are “>=”, for not less than, and “<=” for not greater than. Valid choices for defining two bounds are [“>=”, “<=”] or [“<=”, “>=”].

  • diff_for_warning (float) – If assigned, the plugin will raise a warning if any absolute change in forecast value is greater than this value.

Returns:

A forecast cube with identical metadata to forecast but the forecasts are enforced to adhere to the defined bounds.

Return type:

iris.cube.Cube

Raises:

  • ValueError – if additive_amount, multiplicative_amount, and comparison_operator are of mismatching or incorrect lengths.

  • ValueError – if incorrect number of cubes are provided.