Concentration models settings¶
Calculation settings¶
| Name | Description |
|---|---|
Concentration model tier
|
Custom model, or set according to EFSA Guidance 2012. Note: you may need to set the tier separately in sub-modules. |
Default concentration model
|
The concentration model type that will be used as default for all food/substance combinations. If this model type cannot be fitted, e.g., due to a lack of data, a simpler model will be chosen automatically as a fall-back. |
Include MRL fallback model
|
Use the MRL as fallback model in case the occurrence data is insufficient for other concentration modelling options. |
Restrict LOR imputation to authorised uses
|
Specifies whether imputation of factor x LOR should be limited to authorised uses only. |
Non-detects replacement
|
How to replace non-detects (when not co-modelled, as in censored models). |
Factor f (f x LOR)
|
Replace non-detects by Limit Of Reporting (LOR) times this factor. Constant (f), e.g. 0.5. |
MRL Factor (f x MRL)
|
Use f x MRL as concentration estimate of the MRL models. |
Sample based
|
Include co-occurrence of substances in samples in simulations. If checked, substance residue concentrations are sampled using the correlations between values on the same sample. If unchecked, any correlation between substances is ignored, substance residue concentrations are sampled ignoring the correlations between values on the same sample. |
Impute missing values from available values (if unchecked, missing values are imputed with 0)
|
If checked, in procedure of EFSA Guidance 2012, Appendix 1, impute missing values using substance based concentration models. If unchecked, missing values are imputed by 0. |
Correlate imputed values with sample potency
|
If checked, in procedure of EFSA Guidance 2012, Appendix 1, correlate high imputed values with high cumulative potency samples. If unchecked, random imputation. |
Use occurrence frequencies for imputation
|
Use of occurrence frequencies (e.g., agricultural use frequencies) is relevant for imputation of non-detects in the concentration data. Part of the observed non-detects and missing values may be imputed with zero when the occurrence frequency is smaller than 100%. If checked, occurrence frequencies are expected as input of this action, otherwise 100% potential presence is assumed for all substances on all foods. |