Catch up with Oceananigans.jl

benchmarks/benchmark_static_atmosphere.jl

@@ -6,7 +6,7 @@ using JULES
 const timer = TimerOutput()
 const Δt = 1
 
-grid = RegularCartesianGrid(size=(32, 32, 32), length=(1, 1, 1), halo=(2, 2, 2))
+grid = RegularCartesianGrid(size=(32, 32, 32), extent=(1, 1, 1), halo=(2, 2, 2))
 model = CompressibleModel(grid=grid, thermodynamic_variable=Energy())
 time_step!(model, Δt)  # warmup to compile
 

src/JULES.jl

@@ -4,7 +4,7 @@ using Oceananigans
 using Oceananigans: AbstractGrid
 
 using Oceananigans.TurbulenceClosures:
-    ConstantIsotropicDiffusivity, DiffusivityFields, with_tracers
+    IsotropicDiffusivity, DiffusivityFields, with_tracers
 
 export
     Entropy, Energy,

src/Operators/Operators.jl

@@ -5,6 +5,7 @@ using Oceananigans.Grids
 using Oceananigans.Operators
 
 using Oceananigans: AbstractGrid
+using Oceananigans.TurbulenceClosures: IsotropicDiffusivity
 
 export
     kinetic_energy,

src/Operators/compressible_operators.jl

@@ -102,15 +102,15 @@
             * ∂zᵃᵃᶠ(i, j, k, grid, p_over_ρ_diag, tvar, gases, gravity, ρ, ρũ, ρc̃))
 end
 
-@inline function ∂ⱼDᶜⱼ(i, j, k, grid, closure::ConstantIsotropicDiffusivity, tracer_index, ρ, ρc, args...)
+@inline function ∂ⱼDᶜⱼ(i, j, k, grid, closure::IsotropicDiffusivity, tracer_index, ρ, ρc, args...)
     @inbounds κ = closure.κ[tracer_index]
     return (1/Vᵃᵃᶜ(i, j, k, grid)
             * (  δxᶜᵃᵃ(i, j, k, grid, diffusive_flux_x, κ, ρ, ρc)
                + δyᵃᶜᵃ(i, j, k, grid, diffusive_flux_y, κ, ρ, ρc)
                + δzᵃᵃᶜ(i, j, k, grid, diffusive_flux_z, κ, ρ, ρc)))
 end
 
-@inline function ∂ⱼtᶜDᶜⱼ(i, j, k, grid, closure::ConstantIsotropicDiffusivity, tvar_diag,
+@inline function ∂ⱼtᶜDᶜⱼ(i, j, k, grid, closure::IsotropicDiffusivity, tvar_diag,
                          tracer_index, tvar, gases, gravity, ρ, ρũ, ρc̃, ρc, args...)
 
     @inbounds κ = closure.κ[tracer_index]
@@ -120,7 +120,7 @@ end
                   + δzᵃᵃᶜ(i, j, k, grid, diffusive_tvar_flux_z, κ, tvar_diag, tracer_index, tvar, gases, gravity, ρ, ρũ, ρc̃, ρc)))
 end
 
-@inline function ∂ⱼDᵖⱼ(i, j, k, grid, closure::ConstantIsotropicDiffusivity, tracer_index,
+@inline function ∂ⱼDᵖⱼ(i, j, k, grid, closure::IsotropicDiffusivity, tracer_index,
                        p_over_ρ_diag, tvar, gases, gravity, ρ, ρũ, ρc̃, args ...)
 
     @inbounds κ = closure.κ[tracer_index]
@@ -189,34 +189,34 @@ end
 @inline viscous_flux_wx(i, j, k, grid, νᶠᶜᶠ, ρ, ρw, ρu) = ℑxzᶠᵃᶠ(i, j, k, grid, ρ) * νᶠᶜᶠ * Axᵃᵃᶠ(i, j, k, grid) * strain_rate_tensor_wx(i, j, k, grid, ρ, ρw, ρu)
 @inline viscous_flux_wy(i, j, k, grid, νᶜᶠᶠ, ρ, ρw, ρv) = ℑyzᵃᶠᶠ(i, j, k, grid, ρ) * νᶜᶠᶠ * Ayᵃᵃᶠ(i, j, k, grid) * strain_rate_tensor_wy(i, j, k, grid, ρ, ρw, ρv)
 
-@inline ∂ⱼτ₁ⱼ(i, j, k, grid, closure::ConstantIsotropicDiffusivity, ρ, ρũ, args...) =
+@inline ∂ⱼτ₁ⱼ(i, j, k, grid, closure::IsotropicDiffusivity, ρ, ρũ, args...) =
     (1/Vᵃᵃᶜ(i, j, k, grid)
         * (  δxᶠᵃᵃ(i, j, k, grid, viscous_flux_ux, closure.ν, ρ, ρũ.ρu)
            + δyᵃᶜᵃ(i, j, k, grid, viscous_flux_uy, closure.ν, ρ, ρũ.ρu, ρũ.ρv)
            + δzᵃᵃᶜ(i, j, k, grid, viscous_flux_uz, closure.ν, ρ, ρũ.ρu, ρũ.ρw)))
 
-@inline ∂ⱼτ₂ⱼ(i, j, k, grid, closure::ConstantIsotropicDiffusivity, ρ, ρũ, args...) =
+@inline ∂ⱼτ₂ⱼ(i, j, k, grid, closure::IsotropicDiffusivity, ρ, ρũ, args...) =
     (1/Vᵃᵃᶜ(i, j, k, grid)
         * (  δxᶜᵃᵃ(i, j, k, grid, viscous_flux_vx, closure.ν, ρ, ρũ.ρv, ρũ.ρu)
            + δyᵃᶠᵃ(i, j, k, grid, viscous_flux_vy, closure.ν, ρ, ρũ.ρv)
            + δzᵃᵃᶜ(i, j, k, grid, viscous_flux_vz, closure.ν, ρ, ρũ.ρv, ρũ.ρw)))
 
-@inline ∂ⱼτ₃ⱼ(i, j, k, grid, closure::ConstantIsotropicDiffusivity, ρ, ρũ, args...) =
+@inline ∂ⱼτ₃ⱼ(i, j, k, grid, closure::IsotropicDiffusivity, ρ, ρũ, args...) =
     (1/Vᵃᵃᶠ(i, j, k, grid)
         * (  δxᶜᵃᵃ(i, j, k, grid, viscous_flux_wx, closure.ν, ρ, ρũ.ρw, ρũ.ρu)
            + δyᵃᶜᵃ(i, j, k, grid, viscous_flux_wy, closure.ν, ρ, ρũ.ρw, ρũ.ρv)
            + δzᵃᵃᶠ(i, j, k, grid, viscous_flux_wz, closure.ν, ρ, ρũ.ρw)))
 
-@inline u₁∂ⱼτ₁ⱼ(i, j, k, grid, closure::ConstantIsotropicDiffusivity, ρ, ρũ, args...) =
+@inline u₁∂ⱼτ₁ⱼ(i, j, k, grid, closure::IsotropicDiffusivity, ρ, ρũ, args...) =
     U_over_ρ(i, j, k, grid, ρ, ρũ.ρu) * ∂ⱼτ₁ⱼ(i, j, k, grid, closure, ρ, ρũ, args...)
 
-@inline u₂∂ⱼτ₂ⱼ(i, j, k, grid, closure::ConstantIsotropicDiffusivity, ρ, ρũ, args...) =
+@inline u₂∂ⱼτ₂ⱼ(i, j, k, grid, closure::IsotropicDiffusivity, ρ, ρũ, args...) =
     V_over_ρ(i, j, k, grid, ρ, ρũ.ρv) * ∂ⱼτ₂ⱼ(i, j, k, grid, closure, ρ, ρũ, args...)
 
-@inline u₃∂ⱼτ₃ⱼ(i, j, k, grid, closure::ConstantIsotropicDiffusivity, ρ, ρũ, args...) =
+@inline u₃∂ⱼτ₃ⱼ(i, j, k, grid, closure::IsotropicDiffusivity, ρ, ρũ, args...) =
     W_over_ρ(i, j, k, grid, ρ, ρũ.ρw) * ∂ⱼτ₃ⱼ(i, j, k, grid, closure, ρ, ρũ, args...)
 
-@inline Q_dissipation(i, j, k, grid, closure::ConstantIsotropicDiffusivity, ρ, ρũ, args...) =
+@inline Q_dissipation(i, j, k, grid, closure::IsotropicDiffusivity, ρ, ρũ, args...) =
     (  ℑxᶜᵃᵃ(i, j, k, grid, u₁∂ⱼτ₁ⱼ, closure, ρ, ρũ, args...)
      + ℑyᵃᶜᵃ(i, j, k, grid, u₂∂ⱼτ₂ⱼ, closure, ρ, ρũ, args...)
      + ℑzᵃᵃᶜ(i, j, k, grid, u₃∂ⱼτ₃ⱼ, closure, ρ, ρũ, args...))

src/compressible_model.jl

@@ -1,6 +1,6 @@
 using Oceananigans
 using Oceananigans.Models: AbstractModel, Clock, tracernames
-using Oceananigans.Forcing: zeroforcing
+using Oceananigans.Forcings: model_forcing
 
 #####
 ##### Definition of a compressible model
@@ -48,9 +48,10 @@ function CompressibleModel(;
              extra_tracers = nothing,
                tracernames = collect_tracers(thermodynamic_variable, gases, microphysics, extra_tracers),
                   coriolis = nothing,
-                   closure = ConstantIsotropicDiffusivity(float_type, ν=0.5, κ=0.5),
-             diffusivities = DiffusivityFields(architecture, grid, tracernames, closure),
-                   forcing = ModelForcing(),
+                   closure = IsotropicDiffusivity(float_type, ν=0.5, κ=0.5),
+       boundary_conditions = NamedTuple(),
+             diffusivities = DiffusivityFields(architecture, grid, tracernames, boundary_conditions, closure),
+                   forcing = NamedTuple(),
                    gravity = g_Earth,
              slow_forcings = ForcingFields(architecture, grid, tracernames),
           right_hand_sides = RightHandSideFields(architecture, grid, tracernames),
@@ -59,7 +60,7 @@ function CompressibleModel(;
 
     gravity = float_type(gravity)
     tracers = TracerFields(architecture, grid, tracernames)
-    forcing = ModelForcing(tracernames, forcing)
+    forcing = model_forcing(tracernames; forcing...)
     closure = with_tracers(tracernames, closure)
     total_density = CellField(architecture, grid)
 

src/time_stepping.jl

@@ -2,7 +2,9 @@ using JULES.Operators
 
 using Oceananigans: datatuple
 using Oceananigans.BoundaryConditions
-import Oceananigans: time_step!
+
+import Oceananigans.TimeSteppers: time_step!
+import Oceananigans.Simulations: ab2_or_rk3_time_step!
 
 #####
 ##### Utilities for time stepping
@@ -18,8 +20,10 @@ end
 ##### Time-stepping algorithm
 #####
 
+ab2_or_rk3_time_step!(model::CompressibleModel, Δt; euler) = time_step!(model, Δt)
+
 # Adding kwargs... so this time_step! can work with Oceananigans.Simulation
-function time_step!(model::CompressibleModel, Δt; kwargs...)
+function time_step!(model::CompressibleModel, Δt)
     ρ  = model.total_density
     ρũ = model.momenta
     ρc̃ = model.tracers
@@ -43,13 +47,16 @@ function time_step!(model::CompressibleModel, Δt; kwargs...)
 
     @debug "Computing slow forcings..."
     update_total_density!(ρ, model.grid, model.gases, ρc̃)
-    fill_halo_regions!(merge((Σρ=ρ,), ρũ, ρc̃), model.architecture)
+    fill_halo_regions!(merge((Σρ=ρ,), ρũ, ρc̃), model.architecture, model.clock, nothing)
+
+    fill_halo_regions!(ρũ.ρw, model.architecture, model.clock, nothing)
+    fill_halo_regions!(IV_ρũ.ρw, model.architecture, model.clock, nothing)
 
     compute_slow_forcings!(
         F̃, model.grid, model.thermodynamic_variable, model.gases, model.gravity,
-        model.coriolis, model.closure, ρ, ρũ, ρc̃, K̃, model.forcing, model.clock.time)
+        model.coriolis, model.closure, ρ, ρũ, ρc̃, K̃, model.forcing, model.clock)
 
-    fill_halo_regions!(F̃.ρw, model.architecture)
+    fill_halo_regions!(F̃.ρw, model.architecture, model.clock, nothing)
 
     for rk3_iter in 1:3
         @debug "RK3 step #$rk3_iter..."
@@ -60,15 +67,18 @@ function time_step!(model::CompressibleModel, Δt; kwargs...)
                                 model.gases, model.gravity, ρ, ρũ, ρc̃, F̃)
 
             update_total_density!(ρ, model.grid, model.gases, ρc̃)
-            fill_halo_regions!(merge((Σρ=ρ,), ρũ, ρc̃), model.architecture)
+            fill_halo_regions!(merge((Σρ=ρ,), ρũ, ρc̃), model.architecture, model.clock, nothing)
         else
             compute_rhs_args = (R̃, model.grid, model.thermodynamic_variable,
                                 model.gases, model.gravity, ρ, IV_ρũ, IV_ρc̃, F̃)
 
             update_total_density!(ρ, model.grid, model.gases, IV_ρc̃)
-            fill_halo_regions!(merge((Σρ=ρ,), IV_ρũ, IV_ρc̃), model.architecture)
+            fill_halo_regions!(merge((Σρ=ρ,), IV_ρũ, IV_ρc̃), model.architecture, model.clock, nothing)
         end
 
+        fill_halo_regions!(ρũ.ρw, model.architecture, model.clock, nothing)
+        fill_halo_regions!(IV_ρũ.ρw, model.architecture, model.clock, nothing)
+
         compute_right_hand_sides!(compute_rhs_args...)
 
         @debug "  Advancing variables..."

src/time_stepping_kernels.jl

@@ -15,12 +15,12 @@ update_total_density!(model) =
 """
 Slow forcings include viscous dissipation, diffusion, and Coriolis terms.
 """
-function compute_slow_forcings!(F̃, grid, tvar, gases, gravity, coriolis, closure, ρ, ρũ, ρc̃, K̃, forcing, time)
+function compute_slow_forcings!(F̃, grid, tvar, gases, gravity, coriolis, closure, ρ, ρũ, ρc̃, K̃, forcing, clock)
     @inbounds begin
         for k in 1:grid.Nz, j in 1:grid.Ny, i in 1:grid.Nx
-            F̃.ρu[i, j, k] = FU(i, j, k, grid, coriolis, closure, ρ, ρũ, K̃) + forcing.u(i, j, k, grid, time, ρũ, ρc̃, nothing)
-            F̃.ρv[i, j, k] = FV(i, j, k, grid, coriolis, closure, ρ, ρũ, K̃) + forcing.v(i, j, k, grid, time, ρũ, ρc̃, nothing)
-            F̃.ρw[i, j, k] = FW(i, j, k, grid, coriolis, closure, ρ, ρũ, K̃) + forcing.w(i, j, k, grid, time, ρũ, ρc̃, nothing)
+            F̃.ρu[i, j, k] = FU(i, j, k, grid, coriolis, closure, ρ, ρũ, K̃) + forcing.u(i, j, k, grid, clock, nothing)
+            F̃.ρv[i, j, k] = FV(i, j, k, grid, coriolis, closure, ρ, ρũ, K̃) + forcing.v(i, j, k, grid, clock, nothing)
+            F̃.ρw[i, j, k] = FW(i, j, k, grid, coriolis, closure, ρ, ρũ, K̃) + forcing.w(i, j, k, grid, clock, nothing)
         end
 
         for (tracer_index, ρc_name) in enumerate(propertynames(ρc̃))

test/test_lazy_fields.jl

@@ -3,7 +3,7 @@ using JULES: LazyVelocityFields, LazyTracerFields
 @testset "Lazy fields" begin
     @info "Testing lazy fields..."
 
-    grid = RegularCartesianGrid(size=(16, 16, 16), length=(1, 1, 1))
+    grid = RegularCartesianGrid(size=(16, 16, 16), extent=(1, 1, 1))
     model = CompressibleModel(grid=grid, gases=DryEarth(),
                               thermodynamic_variable=Energy())
 
@@ -22,7 +22,7 @@ using JULES: LazyVelocityFields, LazyTracerFields
 
     @test primitive_tracers.e[10, 11, 12] == 4/π
 
-    grid = RegularCartesianGrid(size=(16, 16, 16), length=(1, 1, 1))
+    grid = RegularCartesianGrid(size=(16, 16, 16), extent=(1, 1, 1))
     model = CompressibleModel(grid=grid, gases=DryEarth(),
                               thermodynamic_variable=Entropy())
 

test/test_models.jl

@@ -4,7 +4,7 @@
     @testset "Energy thermodynamic variable" begin
         @info "  Testing model construction with energy thermodynamic variable..."
 
-        grid = RegularCartesianGrid(size=(16, 16, 16), length=(1, 1, 1))
+        grid = RegularCartesianGrid(size=(16, 16, 16), extent=(1, 1, 1))
         model = CompressibleModel(grid = grid, gases = DryEarth(),
                                   thermodynamic_variable = Energy())
         @test model isa CompressibleModel
@@ -13,7 +13,7 @@
     @testset "Entropy thermodynamic variable" begin
         @info "  Testing model construction with entropy thermodynamic variable..."
 
-        grid = RegularCartesianGrid(size=(16, 16, 16), length=(1, 1, 1))
+        grid = RegularCartesianGrid(size=(16, 16, 16), extent=(1, 1, 1))
         model = CompressibleModel(grid = grid, gases = DryEarth(),
                                   thermodynamic_variable = Entropy())
         @test model isa CompressibleModel

test/test_regression.jl

@@ -1,17 +1,20 @@
 using Oceananigans.Fields: interiorparent
 
-function summarize_regression_test(field_names, fields, correct_fields)
-    for (field_name, φ, φ_c) in zip(field_names, fields, correct_fields)
-        Δ = Array(φ) .- φ_c
+function summarize_regression_test(fields, correct_fields)
+    for (field_name, φ, φ_c) in zip(keys(fields), fields, correct_fields)
+        Δ = φ .- φ_c
 
         Δ_min      = minimum(Δ)
         Δ_max      = maximum(Δ)
         Δ_mean     = mean(Δ)
         Δ_abs_mean = mean(abs, Δ)
         Δ_std      = std(Δ)
 
-        @info(@sprintf("Δ%s: min=%.6e, max=%.6e, mean=%.6e, absmean=%.6e, std=%.6e",
-                       field_name, Δ_min, Δ_max, Δ_mean, Δ_abs_mean, Δ_std))
+        matching    = sum(φ .≈ φ_c)
+        grid_points = length(φ_c)
+
+        @info @sprintf("Δ%s: min=%+.6e, max=%+.6e, mean=%+.6e, absmean=%+.6e, std=%+.6e (%d/%d matching grid points)",
+                       field_name, Δ_min, Δ_max, Δ_mean, Δ_abs_mean, Δ_std, matching, grid_points)
     end
 end
 
@@ -61,7 +64,9 @@ end
                 push!(correct_fields, file["ρs"])
             end
 
-            summarize_regression_test(field_names, fields, correct_fields)
+            fields = NamedTuple{Tuple(field_names)}(Tuple(fields))
+            correct_fields = NamedTuple{Tuple(field_names)}(Tuple(correct_fields))
+            summarize_regression_test(fields, correct_fields)
 
             @test all(isapprox.(interior(model.momenta.ρu), file["ρu"], atol=1e-12))
 
@@ -125,7 +130,9 @@ end
                 push!(correct_fields, file["ρs"])
             end
 
-            summarize_regression_test(field_names, fields, correct_fields)
+            fields = NamedTuple{Tuple(field_names)}(Tuple(fields))
+            correct_fields = NamedTuple{Tuple(field_names)}(Tuple(correct_fields))
+            summarize_regression_test(fields, correct_fields)
 
             @test all(isapprox.(interior(model.momenta.ρu), file["ρu"], atol=1e-12))
 

test/test_time_stepping.jl

@@ -4,7 +4,7 @@
     @testset "Energy thermodynamic variable" begin
         @info "  Testing time stepping with energy thermodynamic variable..."
 
-        grid = RegularCartesianGrid(size=(16, 16, 16), halo=(2, 2, 2), length=(1, 1, 1))
+        grid = RegularCartesianGrid(size=(16, 16, 16), halo=(2, 2, 2), extent=(1, 1, 1))
         model = CompressibleModel(grid = grid, gases = DryEarth(),
                                   thermodynamic_variable = Energy())
         time_step!(model, 1)
@@ -14,7 +14,7 @@
     @testset "Entropy thermodynamic variable" begin
         @info "  Testing time stepping with entropy thermodynamic variable..."
 
-        grid = RegularCartesianGrid(size=(16, 16, 16), halo=(2, 2, 2), length=(1, 1, 1))
+        grid = RegularCartesianGrid(size=(16, 16, 16), halo=(2, 2, 2), extent=(1, 1, 1))
         model = CompressibleModel(grid = grid, gases = DryEarth(),
                                   thermodynamic_variable = Entropy())
         time_step!(model, 1)

verification/dry_rising_thermal_bubble/dry_rising_thermal_bubble.jl

@@ -34,7 +34,7 @@ function simulate_dry_rising_thermal_bubble(; thermodynamic_variable, end_time=1
                           grid = grid,
                          gases = DryEarth(),
         thermodynamic_variable = tvar,
-                       closure = ConstantIsotropicDiffusivity(ν=75.0, κ=75.0)
+                       closure = IsotropicDiffusivity(ν=75.0, κ=75.0)
     )
 
     #####
@@ -130,7 +130,7 @@ function simulate_dry_rising_thermal_bubble(; thermodynamic_variable, end_time=1
         sim_parameters = (make_plots=make_plots, ρʰᵈ=ρʰᵈ, ρ̄ᵢ=ρ̄ᵢ, ρ̄s̄ᵢ=ρ̄s̄ᵢ)
     end
 
-    simulation = Simulation(model, Δt=0.1, stop_time=end_time, progress_frequency=50,
+    simulation = Simulation(model, Δt=0.1, stop_time=end_time, iteration_interval=50,
                             progress=print_progress_and_make_plots, parameters=sim_parameters)
     run!(simulation)
 
@@ -209,7 +209,7 @@ function print_progress_and_make_plots(simulation)
 
         p = plot(u_plot, w_plot, ρ_plot, tvar_plot, layout=(2, 2), dpi=200, show=true)
 
-        n = Int(model.clock.iteration / simulation.progress_frequency)
+        n = Int(model.clock.iteration / simulation.iteration_interval)
         n == 1 && !isdir("frames") && mkdir("frames")
         savefig(p, @sprintf("frames/thermal_bubble_%s_%03d.png", typeof(tvar), n))
     end

verification/nonlinear_density_current/nonlinear_density_current.jl

@@ -39,7 +39,7 @@ model = CompressibleModel(
                       grid = grid,
                      gases = DryEarth(),
     thermodynamic_variable = tvar,
-                   closure = ConstantIsotropicDiffusivity(ν=75.0, κ=75.0)
+                   closure = IsotropicDiffusivity(ν=75.0, κ=75.0)
 )
 
 #####

verification/three_gas_dry_rising_thermal_bubble/three_gas_dry_rising_thermal_bubble.jl

@@ -32,7 +32,7 @@ function simulate_three_gas_dry_rising_thermal_bubble(;
                           grid = grid,
                          gases = DryEarth3(),
         thermodynamic_variable = tvar,
-                       closure = ConstantIsotropicDiffusivity(ν=75.0, κ=75.0)
+                       closure = IsotropicDiffusivity(ν=75.0, κ=75.0)
     )
 
     #####
@@ -164,7 +164,7 @@ function simulate_three_gas_dry_rising_thermal_bubble(;
         sim_parameters = (make_plots=make_plots, ρʰᵈ=ρʰᵈ, ρ̄ᵢ=ρ̄ᵢ, ρ̄s̄ᵢ=ρ̄s̄ᵢ)
     end
 
-    simulation = Simulation(model, Δt=0.1, stop_time=end_time, progress_frequency=50,
+    simulation = Simulation(model, Δt=0.1, stop_time=end_time, iteration_interval=50,
                             progress=print_progress_and_make_plots, parameters=sim_parameters)
     run!(simulation)
 
@@ -253,7 +253,7 @@ function print_progress_and_make_plots(simulation)
         p = plot(ρ₁_plot, ρ₂_plot, ρ₃_plot, ρ_plot, ρ′_plot, tvar_plot,
                  layout=(2, 3), show=true, dpi=200)
 
-        n = Int(model.clock.iteration / simulation.progress_frequency)
+        n = Int(model.clock.iteration / simulation.iteration_interval)
         n == 1 && !isdir("frames") && mkdir("frames")
         savefig(p, @sprintf("frames/three_gas_thermal_bubble_%s_%03d.png", typeof(tvar), n))
     end