Implement suggestions

examples/tree_2d_dgsem/elixir_eulermulti_shock_bubble_shockcapturing_subcell_minmax.jl

@@ -88,9 +88,8 @@ volume_flux = flux_ranocha
 basis = LobattoLegendreBasis(3)
 
 limiter_idp = SubcellLimiterIDP(equations, basis;
-                                local_minmax_variables_cons = [
-                                    ("rho" * string(i) for i in eachcomponent(equations))...,
-                                ])
+                                local_minmax_variables_cons = ["rho" * string(i)
+                                                               for i in eachcomponent(equations)])
 volume_integral = VolumeIntegralSubcellLimiting(limiter_idp;
                                                 volume_flux_dg = volume_flux,
                                                 volume_flux_fv = surface_flux)

examples/tree_2d_dgsem/elixir_eulermulti_shock_bubble_shockcapturing_subcell_positivity.jl

@@ -88,9 +88,8 @@ volume_flux = flux_ranocha
 basis = LobattoLegendreBasis(3)
 
 limiter_idp = SubcellLimiterIDP(equations, basis;
-                                positivity_variables_cons = [
-                                    ("rho" * string(i) for i in eachcomponent(equations))...,
-                                ])
+                                positivity_variables_cons = ["rho" * string(i)
+                                                             for i in eachcomponent(equations)])
 
 volume_integral = VolumeIntegralSubcellLimiting(limiter_idp;
                                                 volume_flux_dg = volume_flux,

src/equations/equations.jl

@@ -42,6 +42,22 @@ Common choices of the `conversion_function` are [`cons2cons`](@ref) and
 """
 function varnames end
 
+"""
+    get_variable_index(variable, equations, conversion_function = cons2cons)
+
+Return the index of `variable` in `varnames(conversion_function, equations)` if available.
+Otherwise, return an error.
+"""
+@inline function get_variable_index(variable, equations,
+                                    conversion_function = cons2cons)
+    index = findfirst(==(variable), varnames(conversion_function, equations))
+    if isnothing(index)
+        error("$variable is no valid variable.")
+    end
+
+    return index
+end
+
 # Add methods to show some information on systems of equations.
 function Base.show(io::IO, equations::AbstractEquations)
     # Since this is not performance-critical, we can use `@nospecialize` to reduce latency.
@@ -211,17 +227,17 @@ end
 """
     NonConservativeLocal()
 
-Struct used for multiple dispatch on non-conservative flux functions in the format of "local * symmetric". 
-When the argument `nonconservative_type` is of type `NonConservativeLocal`, 
+Struct used for multiple dispatch on non-conservative flux functions in the format of "local * symmetric".
+When the argument `nonconservative_type` is of type `NonConservativeLocal`,
 the function returns the local part of the non-conservative term.
 """
 struct NonConservativeLocal end
 
 """
     NonConservativeSymmetric()
 
-Struct used for multiple dispatch on non-conservative flux functions in the format of "local * symmetric". 
-When the argument `nonconservative_type` is of type `NonConservativeSymmetric`, 
+Struct used for multiple dispatch on non-conservative flux functions in the format of "local * symmetric".
+When the argument `nonconservative_type` is of type `NonConservativeSymmetric`,
 the function returns the symmetric part of the non-conservative term.
 """
 struct NonConservativeSymmetric end

src/solvers/dgsem_tree/subcell_limiters.jl

@@ -14,17 +14,17 @@ end
 
 """
     SubcellLimiterIDP(equations::AbstractEquations, basis;
-                      local_minmax_variables_cons = [],
-                      positivity_variables_cons = [],
+                      local_minmax_variables_cons = String[],
+                      positivity_variables_cons = String[],
                       positivity_correction_factor = 0.1)
 
 Subcell invariant domain preserving (IDP) limiting used with [`VolumeIntegralSubcellLimiting`](@ref)
 including:
 - Local maximum/minimum Zalesak-type limiting for conservative variables (`local_minmax_variables_cons`)
 - Positivity limiting for conservative variables (`positivity_variables_cons`)
 
-Conservative variables to be limited are passed as a strings, e.g. `local_minmax_variables_cons = ["rho"]`
-and `positivity_variables_nonlinear = ["rho"]`.
+Conservative variables to be limited are passed as a vector of strings, e.g. `local_minmax_variables_cons = ["rho"]`
+and `positivity_variables_cons = ["rho"]`.
 
 The bounds are calculated using the low-order FV solution. The positivity limiter uses
 `positivity_correction_factor` such that `u^new >= positivity_correction_factor * u^FV`.
@@ -56,22 +56,16 @@ end
 
 # this method is used when the limiter is constructed as for shock-capturing volume integrals
 function SubcellLimiterIDP(equations::AbstractEquations, basis;
-                           local_minmax_variables_cons = [],
-                           positivity_variables_cons = [],
+                           local_minmax_variables_cons = String[],
+                           positivity_variables_cons = String[],
                            positivity_correction_factor = 0.1)
     local_minmax = (length(local_minmax_variables_cons) > 0)
     positivity = (length(positivity_variables_cons) > 0)
 
-    variables = varnames(cons2cons, equations)
-    local_minmax_variables_cons_ = Vector{Int}(undef,
-                                               length(local_minmax_variables_cons))
-    positivity_variables_cons_ = Vector{Int}(undef, length(positivity_variables_cons))
-    for (i, variable) in enumerate(local_minmax_variables_cons)
-        local_minmax_variables_cons_[i] = get_variable_index(variable, variables)
-    end
-    for (i, variable) in enumerate(positivity_variables_cons)
-        positivity_variables_cons_[i] = get_variable_index(variable, variables)
-    end
+    local_minmax_variables_cons_ = get_variable_index.(local_minmax_variables_cons,
+                                                       equations)
+    positivity_variables_cons_ = get_variable_index.(positivity_variables_cons,
+                                                     equations)
 
     bound_keys = ()
     if local_minmax
@@ -152,13 +146,4 @@ function get_node_variables!(node_variables, limiter::SubcellLimiterIDP,
 
     return nothing
 end
-
-@inline function get_variable_index(variable, variable_names)
-    for (i_, variable_) in enumerate(variable_names)
-        if variable == variable_
-            return i_
-        end
-    end
-    error("$variable is no valid variable.")
-end
 end # @muladd