NumericalMathematics · JoshuaLampert · Feb 28, 2026 · Feb 28, 2026 · Feb 28, 2026 · Feb 28, 2026
diff --git a/NEWS.md b/NEWS.md
@@ -9,6 +9,8 @@ for human readability.
 
 #### Changed
 
+- There are no default boundary conditions anymore in `Semidiscretization`.
+  Users now have to explicitly provide boundary conditions via the `boundary_conditions` keyword argument, which were periodic by default before ([#286]).
 - `convergence_test` now returns the complete convergence orders. To obtain the mean convergence rates, use `DispersiveShallowWater.calc_mean_convergence` on the convergence orders ([#285]).
 
 ## Changes when updating to v0.9 from v0.8.x

diff --git a/examples/bbm_bbm_1d/bbm_bbm_1d_basic.jl b/examples/bbm_bbm_1d/bbm_bbm_1d_basic.jl
@@ -30,7 +30,7 @@ semi = Semidiscretization(mesh, equations, initial_condition, solver,
 tspan = (0.0, 30.0)
 ode = semidiscretize(semi, tspan)
 summary_callback = SummaryCallback()
-analysis_callback = AnalysisCallback(semi; interval = 10,
+analysis_callback = AnalysisCallback(semi; interval = 50,
                                      extra_analysis_errors = (:conservation_error,),
                                      extra_analysis_integrals = (waterheight_total,
                                                                  velocity, entropy))

diff --git a/examples/bbm_bbm_1d/bbm_bbm_1d_fourier.jl b/examples/bbm_bbm_1d/bbm_bbm_1d_fourier.jl
@@ -32,7 +32,7 @@ semi = Semidiscretization(mesh, equations, initial_condition, solver,
 tspan = (0.0, 30.0)
 ode = semidiscretize(semi, tspan)
 summary_callback = SummaryCallback()
-analysis_callback = AnalysisCallback(semi; interval = 10,
+analysis_callback = AnalysisCallback(semi; interval = 50,
                                      extra_analysis_errors = (:conservation_error,),
                                      extra_analysis_integrals = (waterheight_total,
                                                                  velocity, entropy))

diff --git a/examples/bbm_bbm_1d/bbm_bbm_1d_relaxation.jl b/examples/bbm_bbm_1d/bbm_bbm_1d_relaxation.jl
@@ -30,7 +30,7 @@ semi = Semidiscretization(mesh, equations, initial_condition, solver,
 tspan = (0.0, 30.0)
 ode = semidiscretize(semi, tspan)
 summary_callback = SummaryCallback()
-analysis_callback = AnalysisCallback(semi; interval = 10,
+analysis_callback = AnalysisCallback(semi; interval = 50,
                                      extra_analysis_errors = (:conservation_error,),
                                      extra_analysis_integrals = (waterheight_total,
                                                                  velocity, entropy))

diff --git a/examples/bbm_bbm_1d/bbm_bbm_1d_upwind_relaxation.jl b/examples/bbm_bbm_1d/bbm_bbm_1d_upwind_relaxation.jl
@@ -36,7 +36,7 @@ semi = Semidiscretization(mesh, equations, initial_condition, solver,
 tspan = (0.0, 30.0)
 ode = semidiscretize(semi, tspan)
 summary_callback = SummaryCallback()
-analysis_callback = AnalysisCallback(semi; interval = 10,
+analysis_callback = AnalysisCallback(semi; interval = 50,
                                      extra_analysis_errors = (:conservation_error,),
                                      extra_analysis_integrals = (waterheight_total,
                                                                  velocity, entropy))

diff --git a/examples/hyperbolic_serre_green_naghdi_1d/hyperbolic_serre_green_naghdi_conservation.jl b/examples/hyperbolic_serre_green_naghdi_1d/hyperbolic_serre_green_naghdi_conservation.jl
@@ -58,7 +58,7 @@ ode = semidiscretize(semi, tspan)
 # terminal.
 io = stdout
 summary_callback = SummaryCallback(io)
-analysis_callback = AnalysisCallback(semi; interval = 10, io,
+analysis_callback = AnalysisCallback(semi; interval = 100, io,
                                      extra_analysis_errors = (:conservation_error,),
                                      extra_analysis_integrals = (waterheight_total,
                                                                  momentum,

diff --git a/examples/kdv_1d/kdv_1d_fourier.jl b/examples/kdv_1d/kdv_1d_fourier.jl
@@ -3,7 +3,7 @@ using DispersiveShallowWater
 using SummationByPartsOperators: fourier_derivative_operator
 
 ###############################################################################
-# Semidiscretization of the KdV equation 
+# Semidiscretization of the KdV equation
 
 equations = KdVEquation1D(gravity = 9.81, D = 1.0)
 initial_condition = initial_condition_convergence_test
@@ -28,7 +28,7 @@ tspan = (0.0, 5.0)
 ode = semidiscretize(semi, tspan)
 
 summary_callback = SummaryCallback()
-analysis_callback = AnalysisCallback(semi; interval = 100,
+analysis_callback = AnalysisCallback(semi; interval = 1000,
                                      extra_analysis_errors = (:conservation_error,),
                                      extra_analysis_integrals = (waterheight_total,
                                                                  waterheight, entropy))

diff --git a/examples/kdv_1d/kdv_1d_manufactured.jl b/examples/kdv_1d/kdv_1d_manufactured.jl
@@ -3,7 +3,7 @@ using DispersiveShallowWater
 using SummationByPartsOperators: upwind_operators, periodic_derivative_operator
 
 ###############################################################################
-# Semidiscretization of the KdV equation 
+# Semidiscretization of the KdV equation
 
 equations = KdVEquation1D(gravity = 9.81, D = 1.0)
 
@@ -35,7 +35,7 @@ tspan = (0.0, 1.0)
 ode = semidiscretize(semi, tspan)
 
 summary_callback = SummaryCallback()
-analysis_callback = AnalysisCallback(semi; interval = 100,
+analysis_callback = AnalysisCallback(semi; interval = 500,
                                      extra_analysis_errors = (:conservation_error,),
                                      extra_analysis_integrals = (waterheight_total,
                                                                  waterheight, entropy))

diff --git a/examples/kdv_1d/kdv_1d_non_dim.jl b/examples/kdv_1d/kdv_1d_non_dim.jl
@@ -45,7 +45,7 @@ tspan = (0.0, 50.0)
 ode = semidiscretize(semi, tspan)
 
 summary_callback = SummaryCallback()
-analysis_callback = AnalysisCallback(semi; interval = 100,
+analysis_callback = AnalysisCallback(semi; interval = 2000,
                                      extra_analysis_errors = (:conservation_error,),
                                      extra_analysis_integrals = (waterheight_total,
                                                                  waterheight, entropy))

diff --git a/examples/serre_green_naghdi_1d/serre_green_naghdi_conservation.jl b/examples/serre_green_naghdi_1d/serre_green_naghdi_conservation.jl
@@ -55,7 +55,7 @@ ode = semidiscretize(semi, tspan)
 # terminal.
 io = stdout
 summary_callback = SummaryCallback(io)
-analysis_callback = AnalysisCallback(semi; interval = 10, io,
+analysis_callback = AnalysisCallback(semi; interval = 50, io,
                                      extra_analysis_errors = (:conservation_error,),
                                      extra_analysis_integrals = (waterheight_total,
                                                                  momentum,

diff --git a/examples/serre_green_naghdi_1d/serre_green_naghdi_manufactured.jl b/examples/serre_green_naghdi_1d/serre_green_naghdi_manufactured.jl
@@ -25,7 +25,7 @@ D1 = upwind_operators(periodic_derivative_operator;
                       derivative_order = 1, accuracy_order = 4,
                       xmin = xmin(mesh), xmax = xmax(mesh),
                       N = nnodes(mesh))
-solver = Solver(D1) 
+solver = Solver(D1)
 =#
 
 # for testing central operators use:
@@ -43,7 +43,7 @@ semi = Semidiscretization(mesh, equations, initial_condition, solver,
 tspan = (0.0, 1.2)
 ode = semidiscretize(semi, tspan)
 summary_callback = SummaryCallback()
-analysis_callback = AnalysisCallback(semi; interval = 10,
+analysis_callback = AnalysisCallback(semi; interval = 100,
                                      extra_analysis_errors = (:conservation_error,),
                                      extra_analysis_integrals = (waterheight_total,
                                                                  entropy_modified))

diff --git a/examples/svaerd_kalisch_1d/svaerd_kalisch_1d_manufactured.jl b/examples/svaerd_kalisch_1d/svaerd_kalisch_1d_manufactured.jl
@@ -33,7 +33,7 @@ semi = Semidiscretization(mesh, equations, initial_condition, solver,
 tspan = (0.0, 1.0)
 ode = semidiscretize(semi, tspan)
 summary_callback = SummaryCallback()
-analysis_callback = AnalysisCallback(semi; interval = 1000,
+analysis_callback = AnalysisCallback(semi; interval = 5000,
                                      extra_analysis_errors = (:conservation_error,),
                                      extra_analysis_integrals = (waterheight_total,
                                                                  velocity, entropy))

diff --git a/examples/svaerd_kalisch_1d/svaerd_kalisch_1d_well_balanced.jl b/examples/svaerd_kalisch_1d/svaerd_kalisch_1d_well_balanced.jl
@@ -31,7 +31,7 @@ semi = Semidiscretization(mesh, equations, initial_condition, solver,
 tspan = (0.0, 10.0)
 ode = semidiscretize(semi, tspan)
 summary_callback = SummaryCallback()
-analysis_callback = AnalysisCallback(semi; interval = 100,
+analysis_callback = AnalysisCallback(semi; interval = 1000,
                                      extra_analysis_errors = (:conservation_error,),
                                      extra_analysis_integrals = (waterheight_total,
                                                                  momentum, entropy,

diff --git a/src/semidiscretization.jl b/src/semidiscretization.jl
@@ -43,7 +43,7 @@ end
 """
     Semidiscretization(mesh, equations, initial_condition, solver;
                        source_terms=nothing,
-                       boundary_conditions=boundary_condition_periodic,
+                       boundary_conditions,
                        RealT=real(solver),
                        uEltype=RealT,
                        initial_cache = (tmp1 = Array{RealT}(undef, nnodes(mesh)),
@@ -53,7 +53,7 @@ Construct a semidiscretization of a PDE.
 """
 function Semidiscretization(mesh, equations, initial_condition, solver;
                             source_terms = nothing,
-                            boundary_conditions = boundary_condition_periodic,
+                            boundary_conditions,
                             # `RealT` is used as real type for node locations etc.
                             # while `uEltype` is used as element type of solutions etc.
                             RealT = real(solver), uEltype = RealT,

diff --git a/test/test_unit.jl b/test/test_unit.jl
@@ -88,31 +88,37 @@ end
     initial_condition = initial_condition_dingemans
     mesh = Mesh1D(-138, 46, 10)
     solver = Solver(mesh, 4)
-    semi_flat = Semidiscretization(mesh, equations_flat, initial_condition, solver)
+    semi_flat = Semidiscretization(mesh, equations_flat, initial_condition, solver;
+                                   boundary_conditions = boundary_condition_periodic)
     @test_throws ArgumentError semidiscretize(semi_flat, (0.0, 1.0))
 end
 
 @testitem "Solver consistency" setup=[Setup, AdditionalImports] begin
     mesh = Mesh1D(-1.0, 1.0, 10)
     initial_condition = initial_condition_convergence_test
+    boundary_conditions = boundary_condition_periodic
     D1 = periodic_derivative_operator(1, 4, mesh.xmin, mesh.xmax, mesh.N)
     solver = Solver(D1)
 
     equations = KdVEquation1D(gravity = 1.0)
     @test_throws ArgumentError Semidiscretization(mesh, equations, initial_condition,
-                                                  solver)
+                                                  solver;
+                                                  boundary_conditions = boundary_conditions)
 
     equations = BBMEquation1D(gravity = 1.0)
     @test_throws ArgumentError Semidiscretization(mesh, equations, initial_condition,
-                                                  solver)
+                                                  solver;
+                                                  boundary_conditions = boundary_conditions)
 
     equations = BBMBBMEquations1D(gravity = 1.0)
     @test_throws ArgumentError Semidiscretization(mesh, equations, initial_condition,
-                                                  solver)
+                                                  solver;
+                                                  boundary_conditions = boundary_conditions)
 
     equations = SvaerdKalischEquations1D(gravity = 1.0)
     @test_throws ArgumentError Semidiscretization(mesh, equations, initial_condition,
-                                                  solver)
+                                                  solver;
+                                                  boundary_conditions = boundary_conditions)
 end
 
 @testitem "Boundary conditions" setup=[Setup] begin