[contrasting] consider also the stationary model for selection. consider a level of altitude only if at least 2 altitudes are present & the reference altitude is present.

[contrasting] display individual model fitted with all data (300-4800). Display only the best non-stationary model if it passes the Anderson fit test.

[contrasting] add Gumbel altitudinal models. But so far only the first three models are passing tests (models with quadratic & cross terms are crashing)

This includes models that combine some quadratic aspect & a cross term.
Remove random test

the selection for the model with minimal aic only takes into account models with with finite aic (there are often several models with infinite aic)