captest.capdata.CapData.expanded_uncert

CapData.expanded_uncert(grp_to_term, k=1.96)

Calculate expanded uncertainty of the predicted power.

Adds instrument uncertainty and spatial uncertainty in quadrature and passes the result through the regression to calculate the Systematic Standard Uncertainty, which is then added in quadrature with the Random Standard Uncertainty of the regression and multiplied by the k factor, k.

1. Combine by adding in quadrature the spatial and instrument uncertainties for each measurand. 2. Add the absolute uncertainties from step 1 to each of the respective reporting conditions to determine a value for the reporting condition plus the uncertainty. 3. Calculate the predicted power using the RCs plus uncertainty three times i.e. calculate for each RC plus uncertainty. For example, to estimate the impact of the uncertainty of the reporting irradiance one would calculate expected power using the irradiance RC plus irradiance uncertainty at the reporting irradiance and the original temperature and wind reporting conditions that have not had any uncertainty added to them. 6. Calculate the percent difference between the three new expected power values that include uncertainty of the RCs and the expected power with the unmodified RC. 7. Take the square root of the sum of the squares of those three percent differences to obtain the Systematic Standard Uncertainty (bY).

Expects CapData to have a instrument_uncert and spatial_uncerts attributes with matching keys.

Parameters:

  • grp_to_term (dict) – Map the groups of measurement types to the term in the regression formula that was regressed against an aggregated value (typically mean) from that group.

  • k (numeric) – Coverage factor.

Return type:

Expanded uncertainty as a decimal value.