Method Wrappers

Writing method dictionaries by hand is tedious and error-prone. These helpers create them with consistent keys and labels.

create_method

label, method = create_method(:RK2, :MUSCL, 2; limiter = :VK)
# label  == "RK2MUSCL2(VK)"
# method == Dict(:Time_stepper => :RK2, :Scheme_name => :MUSCL, :Scheme_order => 2,
#                :Limiter_name => :VK, :Limiter_mode => :hard, ...)

Returns label => method, where method uses the namespaced keys of the Configuration Reference.

• Pipeline. Unless sim_func_name is given, IMEX steppers (:IMEXEuler, :ARS222, :ARS233, :PRSSP3, :SSP332) select :run_kinetic_simulation and all others :run_direct_simulation.
• Label. "<stepper><scheme><order>", followed in parentheses by any non-default flux, the limiter, and for MOOD the strategy (plus the criterion if it is not :U2). Examples: "RK2MUSCL2", "RK2MUSCL2(VK)", "RK2MUSCL2(EPD1)", "RK2MUSCL2(EPD2,U1)", "RK4MUSCL3(Upwind,minmod)". custom_label replaces it.
• Extra keywords are stored as additional keys, e.g. Scheme_upwind_alg_nd = :Classic or MOOD_delta_relax = 1e-4. String values are converted to Symbols.
• ignore lists parameters the method should ignore. The built-in direct methods pass the kinetic keys (ignore_relax).

The :Upwind scheme only exists at order 1.

get_master_method_dict

Returns all built-in methods as Dict(label => method):

• first-order baselines: EulerUpwind1, RK2Upwind1, IMEXEulerUpwind1, ARS222Upwind1, ARS233Upwind1, and RK2WENO2;
• direct second order: RK2MUSCL2 without limiter, with VK, BJ or minmod, and with MOOD (EPD0, EPD1, EPD2, SEPD0, U1), plus RK2MUSCL1;
• kinetic second order: ARS222MUSCL2 without limiter, with VK or minmod, and with MOOD (EPD1, EPD2, SEPD0, U1);
• high order: RK4MUSCL2–RK4MUSCL5 without limiter, with VK, minmod, or MOOD (EPD1, EPD2), RK4MUSCL4(EPD1,only), and kinetic ARS233MUSCL2–ARS233MUSCL5 with MOOD.

Select methods by label in a SimulationConfig, e.g. ["RK2MUSCL2", "ARS222MUSCL2"].

generate_relax_params

vels, idx = generate_relax_params(2.0, 2, 1)
# vels == ((2.0, -2.0, 0.0, 0.0), (0.0, 0.0, 2.0, -2.0))
# idx  == [1, 5]

Builds the standard kinetic velocity set: $2D$ kinetic variables per macroscopic variable, with speeds $\pm v$ along each axis. It returns the speeds in the format expected by :Kinetic_velocities and the edges for :Kinetic_indices. See Kinetic Relaxation.

API

create_method(timestepper::Symbol, main_gradient::Symbol, order::Int; kwargs...)

get_master_method_dict()

generate_relax_params(v_mag::Float64, dim::Int, NM::Int)