FixConservatives ignore magnetic field when zero

src/Evolution/Systems/GrMhd/ValenciaDivClean/FixConservatives.hpp

@@ -10,6 +10,7 @@
 #include "Options/Context.hpp"
 #include "Options/String.hpp"
 #include "PointwiseFunctions/GeneralRelativity/TagsDeclarations.hpp"  // IWYU pragma: keep
+#include "PointwiseFunctions/Hydro/MagneticFieldTreatment.hpp"
 #include "Utilities/Gsl.hpp"
 #include "Utilities/TMPL.hpp"
 
@@ -160,11 +161,17 @@ class FixConservatives {
     static constexpr Options::String help = {
         "If true then the limiting is applied."};
   };
+  /// How to treat the magnetic field
+  struct MagneticField {
+    using type = hydro::MagneticFieldTreatment;
+    static constexpr Options::String help = {
+        "How to treat the magnetic field."};
+  };
 
   using options =
       tmpl::list<MinimumValueOfD, CutoffD, MinimumValueOfYe, CutoffYe,
                  SafetyFactorForB, SafetyFactorForS, SafetyFactorForSCutoffD,
-                 SafetyFactorForSSlope, Enable>;
+                 SafetyFactorForSSlope, Enable, MagneticField>;
   static constexpr Options::String help = {
       "Variable fixing used in Foucart's thesis.\n"};
 
@@ -176,6 +183,7 @@ class FixConservatives {
                    double safety_factor_for_momentum_density,
                    double safety_factor_for_momentum_density_cutoff_d,
                    double safety_factor_for_momentum_density_slope, bool enable,
+                   hydro::MagneticFieldTreatment magnetic_field_treatment,
                    const Options::Context& context = {});
 
   FixConservatives() = default;
@@ -230,6 +238,8 @@ class FixConservatives {
   double safety_factor_for_momentum_density_slope_{
       std::numeric_limits<double>::signaling_NaN()};
   bool enable_{true};
+  hydro::MagneticFieldTreatment magnetic_field_treatment_{
+      hydro::MagneticFieldTreatment::AssumeNonZero};
 };
 
 bool operator!=(const FixConservatives& lhs, const FixConservatives& rhs);

tests/InputFiles/GrMhd/GhValenciaDivClean/BinaryNeutronStar.yaml

@@ -80,6 +80,7 @@ VariableFixing:
     SafetyFactorForS: 1.0e-4
     SafetyFactorForSCutoffD: 1.0e-8
     SafetyFactorForSSlope: 0.0001
+    MagneticField: AssumeZero
   FixToAtmosphere:
     DensityOfAtmosphere: 1.0e-15
     DensityCutoff: &AtmosphereDensityCutoff 1.1e-15

tests/InputFiles/GrMhd/GhValenciaDivClean/GhMhdBondiMichel.yaml

@@ -77,6 +77,7 @@ VariableFixing:
     SafetyFactorForS: 1.0e-12
     SafetyFactorForSCutoffD: 1.0e-12
     SafetyFactorForSSlope: 0.0
+    MagneticField: AssumeNonZero
   FixToAtmosphere:
     DensityOfAtmosphere: 1.0e-12
     DensityCutoff: 1.0e-12

tests/InputFiles/GrMhd/GhValenciaDivClean/GhMhdTovStar.yaml

@@ -76,6 +76,7 @@ VariableFixing:
     SafetyFactorForS: 1.0e-12
     SafetyFactorForSCutoffD: 1.0e-12
     SafetyFactorForSSlope: 0.0
+    MagneticField: AssumeZero
   FixToAtmosphere:
     DensityOfAtmosphere: 1.0e-12
     DensityCutoff: 1.0e-12

tests/InputFiles/GrMhd/ValenciaDivClean/BlastWave.yaml

@@ -105,6 +105,7 @@ VariableFixing:
     SafetyFactorForS: 1.0e-12
     SafetyFactorForSCutoffD: 1.0e-12
     SafetyFactorForSSlope: 0.0
+    MagneticField: AssumeNonZero
   FixToAtmosphere:
     DensityOfAtmosphere: 1.0e-12
     DensityCutoff: 1.0e-12

tests/InputFiles/GrMhd/ValenciaDivClean/FishboneMoncriefDisk.yaml

@@ -122,6 +122,7 @@ VariableFixing:
     SafetyFactorForS: 1.0e-12
     SafetyFactorForSCutoffD: 1.0e-12
     SafetyFactorForSSlope: 0.0
+    MagneticField: AssumeNonZero
   FixToAtmosphere:
     DensityOfAtmosphere: 1.0e-12
     DensityCutoff: 1.0e-12

tests/Unit/Evolution/Systems/GrMhd/GhValenciaDivClean/Subcell/Test_FixConservativesAndComputePrims.cpp

@@ -22,6 +22,7 @@
 #include "PointwiseFunctions/Hydro/EquationsOfState/Barotropic3D.hpp"
 #include "PointwiseFunctions/Hydro/EquationsOfState/EquationOfState.hpp"
 #include "PointwiseFunctions/Hydro/EquationsOfState/PolytropicFluid.hpp"
+#include "PointwiseFunctions/Hydro/MagneticFieldTreatment.hpp"
 #include "PointwiseFunctions/Hydro/Tags.hpp"
 #include "Utilities/Gsl.hpp"
 #include "Utilities/TMPL.hpp"
@@ -51,7 +52,11 @@ void test(const EquationOfStateType& eos) {
       sqrt(get(determinant(spatial_metric)))};
 
   const grmhd::ValenciaDivClean::FixConservatives variable_fixer{
-      1.e-7, 1.0e-7, 1.0e-10, 1.0e-10, 0.0, 0.0, 1.e-7, 0.0, true};
+      1.e-7,   1.0e-7,
+      1.0e-10, 1.0e-10,
+      0.0,     0.0,
+      1.e-7,   0.0,
+      true,    hydro::MagneticFieldTreatment::AssumeNonZero};
   typename System::variables_tag::type cons_vars{num_pts, 0.0};
   get(get<grmhd::ValenciaDivClean::Tags::TildeD>(cons_vars))[0] = 2.e-12;
   get(get<grmhd::ValenciaDivClean::Tags::TildeYe>(cons_vars))[0] = 2.e-13;

tests/Unit/Evolution/Systems/GrMhd/ValenciaDivClean/Subcell/Test_FixConservativesAndComputePrims.cpp

@@ -15,6 +15,7 @@
 #include "PointwiseFunctions/GeneralRelativity/Tags.hpp"
 #include "PointwiseFunctions/Hydro/EquationsOfState/EquationOfState.hpp"
 #include "PointwiseFunctions/Hydro/EquationsOfState/PolytropicFluid.hpp"
+#include "PointwiseFunctions/Hydro/MagneticFieldTreatment.hpp"
 #include "PointwiseFunctions/Hydro/Tags.hpp"
 
 SPECTRE_TEST_CASE(
@@ -34,7 +35,11 @@ SPECTRE_TEST_CASE(
   }
   const Scalar<DataVector> sqrt_det_spatial_metric{num_pts, 1.0};
   const grmhd::ValenciaDivClean::FixConservatives variable_fixer{
-      1.e-7, 1.0e-7, 1.0e-10, 1.0e-10, 0.0, 0.0, 1.e-7, 0.0, true};
+      1.e-7,   1.0e-7,
+      1.0e-10, 1.0e-10,
+      0.0,     0.0,
+      1.e-7,   0.0,
+      true,    hydro::MagneticFieldTreatment::AssumeNonZero};
   typename System::variables_tag::type cons_vars{num_pts, 0.0};
   get(get<grmhd::ValenciaDivClean::Tags::TildeD>(cons_vars))[0] = 2.e-12;
   get(get<grmhd::ValenciaDivClean::Tags::TildeYe>(cons_vars))[0] = 2.e-13;

tests/Unit/Evolution/Systems/GrMhd/ValenciaDivClean/Test_FixConservatives.cpp

@@ -11,6 +11,7 @@
 #include "Evolution/Systems/GrMhd/ValenciaDivClean/FixConservatives.hpp"
 #include "Framework/TestCreation.hpp"
 #include "Framework/TestHelpers.hpp"
+#include "PointwiseFunctions/Hydro/MagneticFieldTreatment.hpp"
 #include "Utilities/Gsl.hpp"
 #include "Utilities/MakeWithValue.hpp"
 
@@ -129,7 +130,11 @@ void run_benchmark(const bool enable) {
   }
 
   const grmhd::ValenciaDivClean::FixConservatives variable_fixer{
-      1.e-12, 1.0e-11, 1.0e-10, 1.0e-9, 0.0, 0.0, 1.0e-8, 0.0001, true};
+      1.e-12,  1.0e-11,
+      1.0e-10, 1.0e-9,
+      0.0,     0.0,
+      1.0e-8,  0.0001,
+      true,    hydro::MagneticFieldTreatment::AssumeNonZero};
 
   BENCHMARK("FixConservatives") {
     // Note: Benchmarking and perf indicates that software prefetching is likely
@@ -144,7 +149,11 @@ SPECTRE_TEST_CASE("Unit.Evolution.GrMhd.ValenciaDivClean.FixConservatives",
                   "[VariableFixing][Unit]") {
   for (const bool enable : {true, false}) {
     grmhd::ValenciaDivClean::FixConservatives variable_fixer{
-        1.e-12, 1.0e-11, 1.0e-10, 1.0e-9, 0.0, 0.0, 1.e-12, 0.0, enable};
+        1.e-12,  1.0e-11,
+        1.0e-10, 1.0e-9,
+        0.0,     0.0,
+        1.e-12,  0.0,
+        enable,  hydro::MagneticFieldTreatment::AssumeNonZero};
     test_variable_fixer(serialize_and_deserialize(variable_fixer), enable);
     test_serialization(variable_fixer);
   }
@@ -159,7 +168,8 @@ SPECTRE_TEST_CASE("Unit.Evolution.GrMhd.ValenciaDivClean.FixConservatives",
           "SafetyFactorForS: 0.0\n"
           "SafetyFactorForSCutoffD: 1.0e-12\n"
           "SafetyFactorForSSlope: 0.0\n"
-          "Enable: true\n");
+          "Enable: true\n"
+          "MagneticField: AssumeNonZero\n");
   test_variable_fixer(fixer_from_options, true);
 
   run_benchmark(false);