This is an example output tibble from the model_gamm function applied on the Central Baltic Sea food web indicator demonstration data.

model_gamm_ex

Format

A data frame with 234 rows and 16 variables:

id

Numerical IDs for the IND~press combinations.

ind

Indicator names.

press

Pressure names.

model_type

Specification of the model type; at this stage containing only "gam" (Generalized Additive Model).

corrstruc

Specification of the correlation structure; at this stage containing only "none".

aic

AIC of the fitted models

edf

Estimated degrees of freedom for the model terms.

p_val

The p values for the smoothing term (the pressure).

signif_code

The significance codes for the p-values.

r_sq

The adjusted r-squared for the models. Defined as the proportion of variance explained, where original variance and residual variance are both estimated using unbiased estimators. This quantity can be negative if your model is worse than a one parameter constant model, and can be higher for the smaller of two nested models.

nrmse

Absolute values of the root mean square error normalized by the standard deviation (NRMSE) using no back-transformation.

ks_test

The p-values from a Kolmogorov-Smirnov Test applied on the model residuals to test for normal distribution. P-values > 0.05 indicate normally distributed residuals.

tac

logical; indicates whether temporal autocorrelation (TAC) was detected in the residuals. TRUE if model residuals show TAC.

pres_outlier

A list-column with outliers identified for each model (i.e. Cook`s distance > 1). The indices present the position in the training data, including NAs.

excl_outlier

A list-column listing all outliers per model that have been excluded in the GAM fitting

model

A list-column of IND~press-specific gam objects.