Time stepping

Once you're ready to time step the model simply call

time_step!(model; Δt=10)

to take a single time step with step size 10. To take multiple time steps also pass an Nt keyword argument like

time_step!(model; Δt=10, Nt=50)

By default, time_step! uses a first-order forward Euler time step to take the first time step then uses a second-order Adams-Bashforth method for the remaining time steps (which required knowledge of the previous time step). If you are resuming time-stepping then you should not use a forward Euler initialization time step. This can be done via

time_step!(model; Δt=10)
time_step!(model; Δt=10, Nt=50, init_with_euler=false)

Adaptive time stepping

Adaptive time stepping can be acomplished using the TimeStepWizard. It can be used to compute time steps based on capping the CFL number at some value. You must remember to update the time step every so often. For example, to cap the CFL number at 0.3 and update the time step every 50 time steps:

wizard = TimeStepWizard(cfl=0.3, Δt=1.0, max_change=1.2, max_Δt=30.0)

while model.clock.time < end_time
    time_step!(model; Δt=wizard.Δt, Nt=50)
    update_Δt!(wizard, model)
end

See TimeStepWizard for documentation of other features and options.