Give every untyped empty container its element type

CHANGELOG.md

@@ -5,6 +5,9 @@
 ### Changed
 
 - Requires Julia 1.12 or 1.13; 1.10 and 1.11 keep resolving v5.1.1.
+- The Makie `plot!` methods for a `Panel` or a `BodyAerodynamics` return a
+  `Vector{Makie.AbstractPlot}` instead of a `Vector{Any}`; for a `BodyAerodynamics`
+  drawn as flat panels it is one flat list rather than a list per panel.
 
 ## VortexStepMethod v5.1.1 2026-09-12
 

examples/stall_model.jl

@@ -32,19 +32,15 @@ csv_file_path = joinpath(
 )
 
 df = CSV.read(csv_file_path, DataFrame)
-rib_list = []
-for row in eachrow(df)
-    LE = [row.LE_x, row.LE_y, row.LE_z]
-    TE = [row.TE_x, row.TE_y, row.TE_z]
-    push!(rib_list, (LE, TE, LEI_AIRFOIL_BREUKELS,
-                     lei_poly_coeffs(row.d_tube, row.camber)))
-end
 
 # Create wing geometry
 # n_unrefined_sections will be automatically set to the number of ribs (18 sections)
 CAD_wing = Wing(n_panels; spanwise_distribution)
-for rib in rib_list
-    add_section!(CAD_wing, rib[1], rib[2], rib[3], rib[4])
+for row in eachrow(df)
+    LE = [row.LE_x, row.LE_y, row.LE_z]
+    TE = [row.TE_x, row.TE_y, row.TE_z]
+    add_section!(CAD_wing, LE, TE, LEI_AIRFOIL_BREUKELS,
+                 lei_poly_coeffs(row.d_tube, row.camber))
 end
 refine!(CAD_wing)
 body_aero = BodyAerodynamics([CAD_wing])

ext/VortexStepMethodMakieExt.jl

@@ -117,7 +117,7 @@ If `use_observables=true`, creates observables for dynamic updates.
 """
 function Makie.plot!(ax, panel::VortexStepMethod.Panel; color=(:red, 0.2), R_b_w=nothing, T_b_w=nothing,
     use_observables=false, border_linewidth=1.5, transparency=true, kwargs...)
-    plots = []
+    plots = Makie.AbstractPlot[]
     points = panel_plate_geometry(panel; R_b_w, T_b_w)
 
     if use_observables
@@ -253,7 +253,7 @@ function Makie.plot!(ax, body::VortexStepMethod.BodyAerodynamics; color=(:red, 0
     use_observables=false, airfoils=false,
     airfoil_color=:deepskyblue, airfoil_opacity=0.2, rib_color=:black,
     border_linewidth=1.5, transparency=true, kwargs...)
-    plots = []
+    plots = Makie.AbstractPlot[]
 
     if airfoils
         vertices, faces, ribs = airfoil_skin_geometry(body; R_b_w, T_b_w)
@@ -316,9 +316,8 @@ function Makie.plot!(ax, body::VortexStepMethod.BodyAerodynamics; color=(:red, 0
     else
         # Static plotting (original behavior)
         for panel in body.panels
-            p = Makie.plot!(ax, panel; color, R_b_w, T_b_w, use_observables=false,
-                            border_linewidth, transparency, kwargs...)
-            push!(plots, p)
+            append!(plots, Makie.plot!(ax, panel; color, R_b_w, T_b_w,
+                use_observables=false, border_linewidth, transparency, kwargs...))
         end
     end
 
@@ -931,8 +930,8 @@ function VortexStepMethod.plot_polars(
     main_title = replace(title, " " => "_")
 
     # Generate polar data
-    polar_data_list = []
-    cm_data_list = []
+    polar_data_list = Vector{Array{Float64}}[]
+    cm_data_list = NamedTuple{(:cmx, :cmy, :cmz), NTuple{3, Vector{Float64}}}[]
     labels_with_re = copy(label_list)
     for (i, (solver, body_aero)) in enumerate(zip(solver_list, body_aero_list))
         result = VortexStepMethod.generate_polar_data(

src/obj_adapter/obj_geometry.jl

@@ -12,8 +12,8 @@ Read vertices and faces from an OBJ file.
   - faces: Vector of triangle vertex indices
 """
 function read_faces(filename)
-    vertices = []
-    faces = []
+    vertices = Vector{Float64}[]
+    faces = Vector{Int64}[]
 
     open(filename) do file
         for line in eachline(file)

src/panel.jl

@@ -600,7 +600,7 @@ Calculate filaments for plotting with their positions and colors.
   - Color string
 """
 function calculate_filaments_for_plotting(panel::Panel)
-    filaments_plot = []
+    filaments_plot = Tuple{Vector{Float64}, Vector{Float64}, String}[]
 
     for (i, filament) in enumerate(panel.filaments)
         x1 = filament.x1

src/settings.jl

@@ -225,7 +225,7 @@ wing = Wing(settings)
 """
 @Base.kwdef mutable struct VSMSettings
     condition::ConditionSettings = ConditionSettings()
-    wings::Vector{WingSettings} = []
+    wings::Vector{WingSettings} = WingSettings[]
     solver_settings::SolverSettings = SolverSettings()
 end
 

test/panel/test_panel.jl

@@ -95,6 +95,17 @@ end
         @test isapprox(panel.y_airf, [0.0, 1.0, 0.0])
     end
 
+    @testset "Filaments for plotting have a concrete element type" begin
+        section1 = Section([0.0, 0.0, 0.0], [1.0, 0.0, 0.0], INVISCID)
+        section2 = Section([0.0, 10.0, 0.0], [1.0, 10.0, 0.0], INVISCID)
+        panel = create_panel(section1, section2)
+        panel.va = [10.0, 0.0, 0.0]
+
+        filaments = VortexStepMethod.calculate_filaments_for_plotting(panel)
+        @test filaments isa Vector{Tuple{Vector{Float64}, Vector{Float64}, String}}
+        @test length(filaments) == length(panel.filaments)
+    end
+
     @testset "Velocity Calculations" begin
         section1 = Section([0.0, 0.0, 0.0], [1.0, 0.0, 0.0], INVISCID)
         section2 = Section([0.0, 10.0, 0.0], [1.0, 10.0, 0.0], INVISCID)

test/plotting/test_plotting.jl

@@ -284,8 +284,8 @@ end
         write(io_no_cs, "aoa,cl,cd\n0.0,0.10,0.010\n5.0,0.20,0.020\n")
     end
     fig_lit_no_cs = plot_polars(
-        Any[],
-        Any[],
+        Solver[],
+        BodyAerodynamics[],
         ["Literature no CS"];
         literature_path_list=[lit_no_cs_path],
         is_save=false,
@@ -299,8 +299,8 @@ end
         write(io_bad, "alpha,cl\n0.0,0.10\n5.0,0.20\n")
     end
     @test_throws ArgumentError plot_polars(
-        Any[],
-        Any[],
+        Solver[],
+        BodyAerodynamics[],
         ["Literature bad"];
         literature_path_list=[lit_bad_path],
         is_save=false,
@@ -316,8 +316,8 @@ end
             "5.0,0.5,0.02,0.01,0.004,0.005,0.006\n")
     end
     fig_moments = plot_polars(
-        Any[],
-        Any[],
+        Solver[],
+        BodyAerodynamics[],
         ["Literature with moments"];
         literature_path_list=[cm_lit_path],
         show_moments=true,
@@ -334,8 +334,8 @@ end
             "0.0,0.1,0.01\n5.0,0.5,0.02\n")
     end
     fig_no_moments = plot_polars(
-        Any[],
-        Any[],
+        Solver[],
+        BodyAerodynamics[],
         ["Literature no moments"];
         literature_path_list=[no_cm_path],
         show_moments=false,
@@ -453,6 +453,7 @@ end
     ax = Axis3(fig[1, 1])
     plots = Makie.plot!(ax, body_aero; airfoils=true)
     @test !isempty(plots)
+    @test plots isa Vector{Makie.AbstractPlot}
 
     # Observable airfoil-skin plot registers the body for pose updates.
     fig_obs = Figure()
@@ -501,7 +502,9 @@ end
     # border_linewidth flows through the standard (non-airfoil) panel plot.
     fig_lw = Figure()
     ax_lw = Axis3(fig_lw[1, 1])
-    @test_nowarn Makie.plot!(ax_lw, plain_body; border_linewidth=3.0)
+    plots_lw = @test_nowarn Makie.plot!(ax_lw, plain_body; border_linewidth=3.0)
+    @test plots_lw isa Vector{Makie.AbstractPlot}
+    @test length(plots_lw) == 2 * length(plain_body.panels)
 end
 
 @testset "generated_slices reads the deflected .dat under its generated name" begin

test/ram_geometry/test_kite_geometry.jl

@@ -32,6 +32,8 @@ using Serialization
         @test vertices[2] ≈ [1.0, 0.0, 0.0]
         @test vertices[3] ≈ [0.0, 1.0, 0.0]
         @test faces[1] == [1, 2, 3]
+        @test vertices isa Vector{Vector{Float64}}
+        @test faces isa Vector{Vector{Int64}}
     end
 
     @testset "Center of Mass Calculation" begin
@@ -62,10 +64,8 @@ using Serialization
         # Create simple curved wing vertices
         r = 5.0
         z_center = 2.0
-        vertices = []
-        for θ in range(-π/4, π/4, length=100)
-            push!(vertices, [0.0, r*sin(θ), z_center + r*cos(θ)])
-        end
+        vertices = [[0.0, r*sin(θ), z_center + r*cos(θ)]
+                    for θ in range(-π/4, π/4, length=100)]
 
         z, radius, gamma_tip = find_circle_center_and_radius(vertices)
 
@@ -76,7 +76,7 @@ using Serialization
 
     r = 5.0
     @testset "Interpolation Creation" begin
-        vertices = []
+        vertices = Vector{Float64}[]
         z_center = 2.0
         Δθ = π/2 / 1000
         for θ in range(-π/4, π/4-Δθ, 1000)

test/thesis_oriol_cayon.jl

@@ -22,10 +22,10 @@ CD : Global CD
 function output_results(Fmag, aero_coeffs, ringvec, Uinf, controlpoints, Atot)
     rho = 1.225
     alpha = aero_coeffs[:, 1]
-    F_rel = []
-    F_gl = []
-    Fmag_gl = []
-    SideF = []
+    F_rel = Vector{Vector{Float64}}[]
+    F_gl = Vector{Vector{Float64}}[]
+    Fmag_gl = Vector{Float64}[]
+    SideF = Float64[]
     Ltot = 0.0
     Dtot = 0.0
     SFtot = 0.0
@@ -124,12 +124,12 @@ ringvec : List of dictionaries containing the vectors that define each ring
 coord_L : coordinates of the aerodynamic centers of each wing panel
 """
 function create_geometry_general(coordinates, Uinf, N, ring_geo, model)
-    filaments = []
-    controlpoints = []
-    rings = []
-    wingpanels = []
-    ringvec = []
-    coord_L = []
+    filaments = Dict{String, Any}[]
+    controlpoints = Dict{String, Any}[]
+    rings = Vector{Dict{String, Any}}[]
+    wingpanels = Dict{String, Vector{Float64}}[]
+    ringvec = Dict{String, Vector{Float64}}[]
+    coord_L = Vector{Float64}[]
 
     # Go through all wing panels
     for i in 1:N-1
@@ -279,7 +279,7 @@ function create_geometry_general(coordinates, Uinf, N, ring_geo, model)
         end
 
         push!(rings, filaments)
-        filaments = []
+        filaments = Dict{String, Any}[]
     end
 
     coord_L = hcat(coord_L...)

test/yaml_geometry/test_yaml_wing_deformation.jl

@@ -59,14 +59,10 @@ using Test
         body_aero = BodyAerodynamics([wing])
 
         # Store original points for multiple panels
-        original_points = []
         test_indices = [1, length(body_aero.panels) ÷ 2, length(body_aero.panels)]
-        for i in test_indices
-            push!(original_points, (
-                LE=copy(body_aero.panels[i].LE_point_1),
-                TE=copy(body_aero.panels[i].TE_point_1)
-            ))
-        end
+        original_points = [(LE=copy(body_aero.panels[i].LE_point_1),
+                            TE=copy(body_aero.panels[i].TE_point_1))
+                           for i in test_indices]
 
         # Apply spanwise-varying deformation (panel-level)
         n = wing.n_panels