diff --git a/MaterialLib/MPL/Properties/Function.cpp b/MaterialLib/MPL/Properties/Function.cpp
index da9f5f1ff2b..608d6e17acc 100644
--- a/MaterialLib/MPL/Properties/Function.cpp
+++ b/MaterialLib/MPL/Properties/Function.cpp
@@ -25,7 +25,6 @@ static std::vector<exprtk::expression<T>> compileExpressions(
     exprtk::parser<T> parser;
 
     std::vector<exprtk::expression<T>> expressions(string_expressions.size());
-    expressions.resize(string_expressions.size());
     for (unsigned i = 0; i < string_expressions.size(); ++i)
     {
         expressions[i].register_symbol_table(symbol_table);
diff --git a/NumLib/CMakeLists.txt b/NumLib/CMakeLists.txt
index b3a67b4f0e1..6974ec44b62 100644
--- a/NumLib/CMakeLists.txt
+++ b/NumLib/CMakeLists.txt
@@ -11,7 +11,6 @@ append_source_files(SOURCES NumericalStability)
 append_source_files(SOURCES TimeStepping)
 append_source_files(SOURCES TimeStepping/Algorithms)
 append_source_files(SOURCES StaggeredCoupling)
-append_source_files(SOURCES Function)
 append_source_files(SOURCES ODESolver)
 append_source_files(SOURCES Extrapolation)
 
diff --git a/NumLib/Extrapolation/LocalLinearLeastSquaresExtrapolator.cpp b/NumLib/Extrapolation/LocalLinearLeastSquaresExtrapolator.cpp
index fdb76d04c77..f81605eba17 100644
--- a/NumLib/Extrapolation/LocalLinearLeastSquaresExtrapolator.cpp
+++ b/NumLib/Extrapolation/LocalLinearLeastSquaresExtrapolator.cpp
@@ -18,7 +18,7 @@
 #include "MathLib/LinAlg/LinAlg.h"
 #include "MathLib/LinAlg/MatrixVectorTraits.h"
 #include "NumLib/Assembler/SerialExecutor.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 
 namespace NumLib
 {
diff --git a/NumLib/Function/Interpolation.h b/NumLib/Fem/Interpolation.h
similarity index 96%
rename from NumLib/Function/Interpolation.h
rename to NumLib/Fem/Interpolation.h
index bedd5d1eeac..3cd2944af1d 100644
--- a/NumLib/Function/Interpolation.h
+++ b/NumLib/Fem/Interpolation.h
@@ -13,10 +13,10 @@
 #include <array>
 #include <cassert>
 
-#include "NumLib/Fem/CoordinatesMapping/NaturalNodeCoordinates.h"
-#include "NumLib/Fem/FiniteElement/TemplateIsoparametric.h"
-#include "NumLib/Fem/InitShapeMatrices.h"
-#include "NumLib/Fem/ShapeMatrixPolicy.h"
+#include "CoordinatesMapping/NaturalNodeCoordinates.h"
+#include "FiniteElement/TemplateIsoparametric.h"
+#include "InitShapeMatrices.h"
+#include "ShapeMatrixPolicy.h"
 
 namespace NumLib
 {
diff --git a/NumLib/Function/ISpatialFunction.h b/NumLib/Function/ISpatialFunction.h
deleted file mode 100644
index b683e2cd335..00000000000
--- a/NumLib/Function/ISpatialFunction.h
+++ /dev/null
@@ -1,38 +0,0 @@
-/**
- * \file
- * \author Norihiro Watanabe
- * \date   2013-08-13
- *
- * \copyright
- * Copyright (c) 2012-2024, OpenGeoSys Community (http://www.opengeosys.org)
- *            Distributed under a Modified BSD License.
- *              See accompanying file LICENSE.txt or
- *              http://www.opengeosys.org/project/license
- */
-
-#pragma once
-
-#include <vector>
-
-#include "MathLib/Point3d.h"
-
-namespace NumLib
-{
-/**
- * \brief Interface class for any functions of spatial coordinates
- * \f$f(x,y,z)\f$
- */
-class ISpatialFunction
-{
-public:
-    virtual ~ISpatialFunction() = default;
-
-    /**
-     * return a value at the given point
-     * \param pnt  a point object
-     * \return evaluated value
-     */
-    virtual double operator()(const MathLib::Point3d& pnt) const = 0;
-};
-
-}  // namespace NumLib
diff --git a/ProcessLib/BoundaryConditionAndSourceTerm/HCNonAdvectiveFreeComponentFlowBoundaryConditionLocalAssembler.h b/ProcessLib/BoundaryConditionAndSourceTerm/HCNonAdvectiveFreeComponentFlowBoundaryConditionLocalAssembler.h
index 890ac0b915e..72ae581b919 100644
--- a/ProcessLib/BoundaryConditionAndSourceTerm/HCNonAdvectiveFreeComponentFlowBoundaryConditionLocalAssembler.h
+++ b/ProcessLib/BoundaryConditionAndSourceTerm/HCNonAdvectiveFreeComponentFlowBoundaryConditionLocalAssembler.h
@@ -14,7 +14,7 @@
 #include "MeshLib/Elements/MapBulkElementPoint.h"
 #include "MeshLib/PropertyVector.h"
 #include "NumLib/DOF/DOFTableUtil.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "ParameterLib/MeshNodeParameter.h"
 #include "ProcessLib/Process.h"
 
diff --git a/ProcessLib/BoundaryConditionAndSourceTerm/SourceTermIntegrationPointData.h b/ProcessLib/BoundaryConditionAndSourceTerm/SourceTermIntegrationPointData.h
index 33aa3063359..c30f64b9600 100644
--- a/ProcessLib/BoundaryConditionAndSourceTerm/SourceTermIntegrationPointData.h
+++ b/ProcessLib/BoundaryConditionAndSourceTerm/SourceTermIntegrationPointData.h
@@ -12,7 +12,7 @@
 
 #include "MathLib/LinAlg/Eigen/EigenMapTools.h"
 #include "NumLib/Extrapolation/ExtrapolatableElement.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "ProcessLib/LocalAssemblerInterface.h"
 
 namespace ProcessLib
diff --git a/ProcessLib/BoundaryConditionAndSourceTerm/VariableDependentNeumannBoundaryConditionLocalAssembler.h b/ProcessLib/BoundaryConditionAndSourceTerm/VariableDependentNeumannBoundaryConditionLocalAssembler.h
index 898e4b15d3d..2c9ee4ed74f 100644
--- a/ProcessLib/BoundaryConditionAndSourceTerm/VariableDependentNeumannBoundaryConditionLocalAssembler.h
+++ b/ProcessLib/BoundaryConditionAndSourceTerm/VariableDependentNeumannBoundaryConditionLocalAssembler.h
@@ -13,7 +13,7 @@
 #include "GenericNaturalBoundaryConditionLocalAssembler.h"
 #include "MeshLib/PropertyVector.h"
 #include "NumLib/DOF/DOFTableUtil.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "ParameterLib/MeshNodeParameter.h"
 
 namespace ProcessLib
diff --git a/ProcessLib/ComponentTransport/ComponentTransportFEM.h b/ProcessLib/ComponentTransport/ComponentTransportFEM.h
index d9cedbbc2f5..dd017739e74 100644
--- a/ProcessLib/ComponentTransport/ComponentTransportFEM.h
+++ b/ProcessLib/ComponentTransport/ComponentTransportFEM.h
@@ -25,9 +25,9 @@
 #include "NumLib/Fem/FiniteElement/TemplateIsoparametric.h"
 #include "NumLib/Fem/InitShapeMatrices.h"
 #include "NumLib/Fem/Integration/GenericIntegrationMethod.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "NumLib/Fem/ShapeMatrixCache.h"
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
-#include "NumLib/Function/Interpolation.h"
 #include "NumLib/NumericalStability/AdvectionMatrixAssembler.h"
 #include "NumLib/NumericalStability/HydrodynamicDispersion.h"
 #include "ParameterLib/Parameter.h"
diff --git a/ProcessLib/HT/HTLocalAssemblerInterface.h b/ProcessLib/HT/HTLocalAssemblerInterface.h
index 8fcd126c7de..7248e433a47 100644
--- a/ProcessLib/HT/HTLocalAssemblerInterface.h
+++ b/ProcessLib/HT/HTLocalAssemblerInterface.h
@@ -13,7 +13,7 @@
 
 #include "MathLib/LinAlg/Eigen/EigenMapTools.h"
 #include "NumLib/Extrapolation/ExtrapolatableElement.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "ProcessLib/LocalAssemblerInterface.h"
 
 namespace ProcessLib
diff --git a/ProcessLib/HeatConduction/HeatConductionFEM.h b/ProcessLib/HeatConduction/HeatConductionFEM.h
index 3a9e26c6ddb..bb93cc45209 100644
--- a/ProcessLib/HeatConduction/HeatConductionFEM.h
+++ b/ProcessLib/HeatConduction/HeatConductionFEM.h
@@ -22,8 +22,8 @@
 #include "NumLib/Fem/FiniteElement/TemplateIsoparametric.h"
 #include "NumLib/Fem/InitShapeMatrices.h"
 #include "NumLib/Fem/Integration/GenericIntegrationMethod.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
-#include "NumLib/Function/Interpolation.h"
 #include "ProcessLib/LocalAssemblerInterface.h"
 #include "ProcessLib/LocalAssemblerTraits.h"
 
diff --git a/ProcessLib/HeatTransportBHE/LocalAssemblers/HeatTransportBHELocalAssemblerSoil-impl.h b/ProcessLib/HeatTransportBHE/LocalAssemblers/HeatTransportBHELocalAssemblerSoil-impl.h
index 2bf7a701cee..56351127972 100644
--- a/ProcessLib/HeatTransportBHE/LocalAssemblers/HeatTransportBHELocalAssemblerSoil-impl.h
+++ b/ProcessLib/HeatTransportBHE/LocalAssemblers/HeatTransportBHELocalAssemblerSoil-impl.h
@@ -18,8 +18,8 @@
 #include "MaterialLib/MPL/Utils/FormEigenTensor.h"
 #include "MathLib/LinAlg/Eigen/EigenMapTools.h"
 #include "NumLib/Fem/InitShapeMatrices.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
-#include "NumLib/Function/Interpolation.h"
 #include "ProcessLib/HeatTransportBHE/HeatTransportBHEProcessData.h"
 #include "SecondaryData.h"
 
diff --git a/ProcessLib/HydroMechanics/HydroMechanicsFEM-impl.h b/ProcessLib/HydroMechanics/HydroMechanicsFEM-impl.h
index 482f6e97247..07094dc53be 100644
--- a/ProcessLib/HydroMechanics/HydroMechanicsFEM-impl.h
+++ b/ProcessLib/HydroMechanics/HydroMechanicsFEM-impl.h
@@ -21,7 +21,7 @@
 #include "MaterialLib/MPL/Utils/GetSymmetricTensor.h"
 #include "MaterialLib/SolidModels/SelectSolidConstitutiveRelation.h"
 #include "MathLib/KelvinVector.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "ProcessLib/Utils/SetOrGetIntegrationPointData.h"
 
 namespace ProcessLib
diff --git a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerFracture-impl.h b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerFracture-impl.h
index 04145faea9f..0eae2073e14 100644
--- a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerFracture-impl.h
+++ b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerFracture-impl.h
@@ -14,7 +14,7 @@
 #include "MaterialLib/FractureModels/FractureIdentity2.h"
 #include "MathLib/KelvinVector.h"
 #include "NumLib/Fem/InitShapeMatrices.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "ProcessLib/LIE/Common/LevelSetFunction.h"
 #include "ProcessLib/Utils/SetOrGetIntegrationPointData.h"
 
diff --git a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrix-impl.h b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrix-impl.h
index 6371fe136a7..ebc4935c636 100644
--- a/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrix-impl.h
+++ b/ProcessLib/LIE/HydroMechanics/LocalAssembler/HydroMechanicsLocalAssemblerMatrix-impl.h
@@ -16,7 +16,7 @@
 #include "MathLib/KelvinVector.h"
 #include "MeshLib/ElementStatus.h"
 #include "NumLib/Fem/InitShapeMatrices.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "ProcessLib/Deformation/LinearBMatrix.h"
 #include "ProcessLib/Utils/SetOrGetIntegrationPointData.h"
 
diff --git a/ProcessLib/LiquidFlow/LiquidFlowLocalAssembler-impl.h b/ProcessLib/LiquidFlow/LiquidFlowLocalAssembler-impl.h
index 99bc458dfdc..cd817fe5585 100644
--- a/ProcessLib/LiquidFlow/LiquidFlowLocalAssembler-impl.h
+++ b/ProcessLib/LiquidFlow/LiquidFlowLocalAssembler-impl.h
@@ -16,7 +16,7 @@
 #include "MaterialLib/MPL/MaterialSpatialDistributionMap.h"
 #include "MaterialLib/MPL/Utils/FormEigenTensor.h"
 #include "MaterialLib/MPL/VariableType.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 
 namespace ProcessLib
 {
diff --git a/ProcessLib/RichardsComponentTransport/RichardsComponentTransportFEM.h b/ProcessLib/RichardsComponentTransport/RichardsComponentTransportFEM.h
index 0966cea091f..0457f899e9c 100644
--- a/ProcessLib/RichardsComponentTransport/RichardsComponentTransportFEM.h
+++ b/ProcessLib/RichardsComponentTransport/RichardsComponentTransportFEM.h
@@ -19,8 +19,8 @@
 #include "NumLib/Fem/FiniteElement/TemplateIsoparametric.h"
 #include "NumLib/Fem/InitShapeMatrices.h"
 #include "NumLib/Fem/Integration/GenericIntegrationMethod.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
-#include "NumLib/Function/Interpolation.h"
 #include "ParameterLib/Parameter.h"
 #include "ProcessLib/LocalAssemblerInterface.h"
 #include "ProcessLib/ProcessVariable.h"
diff --git a/ProcessLib/RichardsFlow/RichardsFlowFEM.h b/ProcessLib/RichardsFlow/RichardsFlowFEM.h
index db370913951..aeb3c917ff3 100644
--- a/ProcessLib/RichardsFlow/RichardsFlowFEM.h
+++ b/ProcessLib/RichardsFlow/RichardsFlowFEM.h
@@ -23,8 +23,8 @@
 #include "NumLib/Fem/FiniteElement/TemplateIsoparametric.h"
 #include "NumLib/Fem/InitShapeMatrices.h"
 #include "NumLib/Fem/Integration/GenericIntegrationMethod.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
-#include "NumLib/Function/Interpolation.h"
 #include "ParameterLib/Parameter.h"
 #include "ProcessLib/LocalAssemblerInterface.h"
 #include "ProcessLib/LocalAssemblerTraits.h"
diff --git a/ProcessLib/RichardsMechanics/RichardsMechanicsFEM-impl.h b/ProcessLib/RichardsMechanics/RichardsMechanicsFEM-impl.h
index 3e397ca6d26..ca741dea3d3 100644
--- a/ProcessLib/RichardsMechanics/RichardsMechanicsFEM-impl.h
+++ b/ProcessLib/RichardsMechanics/RichardsMechanicsFEM-impl.h
@@ -21,7 +21,7 @@
 #include "MaterialLib/SolidModels/SelectSolidConstitutiveRelation.h"
 #include "MathLib/EigenBlockMatrixView.h"
 #include "MathLib/KelvinVector.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "ProcessLib/Utils/SetOrGetIntegrationPointData.h"
 #include "ProcessLib/Utils/TransposeInPlace.h"
 
diff --git a/ProcessLib/SmallDeformationNonlocal/SmallDeformationNonlocalFEM.h b/ProcessLib/SmallDeformationNonlocal/SmallDeformationNonlocalFEM.h
index 85df322bc86..5c0b788c637 100644
--- a/ProcessLib/SmallDeformationNonlocal/SmallDeformationNonlocalFEM.h
+++ b/ProcessLib/SmallDeformationNonlocal/SmallDeformationNonlocalFEM.h
@@ -25,8 +25,8 @@
 #include "NumLib/Fem/FiniteElement/TemplateIsoparametric.h"
 #include "NumLib/Fem/InitShapeMatrices.h"
 #include "NumLib/Fem/Integration/GenericIntegrationMethod.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
-#include "NumLib/Function/Interpolation.h"
 #include "ParameterLib/Parameter.h"
 #include "ProcessLib/Deformation/BMatrixPolicy.h"
 #include "ProcessLib/Deformation/Divergence.h"
diff --git a/ProcessLib/SteadyStateDiffusion/SteadyStateDiffusionFEM.h b/ProcessLib/SteadyStateDiffusion/SteadyStateDiffusionFEM.h
index 98e023792a1..29eb622b17a 100644
--- a/ProcessLib/SteadyStateDiffusion/SteadyStateDiffusionFEM.h
+++ b/ProcessLib/SteadyStateDiffusion/SteadyStateDiffusionFEM.h
@@ -21,8 +21,8 @@
 #include "NumLib/Fem/FiniteElement/TemplateIsoparametric.h"
 #include "NumLib/Fem/InitShapeMatrices.h"
 #include "NumLib/Fem/Integration/GenericIntegrationMethod.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
-#include "NumLib/Function/Interpolation.h"
 #include "ParameterLib/Parameter.h"
 #include "ProcessLib/LocalAssemblerInterface.h"
 #include "ProcessLib/LocalAssemblerTraits.h"
diff --git a/ProcessLib/StokesFlow/StokesFlowFEM.h b/ProcessLib/StokesFlow/StokesFlowFEM.h
index 7fc9e239053..e5db6709e90 100644
--- a/ProcessLib/StokesFlow/StokesFlowFEM.h
+++ b/ProcessLib/StokesFlow/StokesFlowFEM.h
@@ -22,8 +22,8 @@
 #include "MathLib/LinAlg/Eigen/EigenMapTools.h"
 #include "NumLib/Fem/InitShapeMatrices.h"
 #include "NumLib/Fem/Integration/GenericIntegrationMethod.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
-#include "NumLib/Function/Interpolation.h"
 #include "StokesFlowProcessData.h"
 
 namespace ProcessLib::StokesFlow
diff --git a/ProcessLib/TES/TESLocalAssembler-impl.h b/ProcessLib/TES/TESLocalAssembler-impl.h
index 25fa26228b8..c3c49930faf 100644
--- a/ProcessLib/TES/TESLocalAssembler-impl.h
+++ b/ProcessLib/TES/TESLocalAssembler-impl.h
@@ -14,8 +14,8 @@
 #include "NumLib/DOF/DOFTableUtil.h"
 #include "NumLib/Fem/FiniteElement/TemplateIsoparametric.h"
 #include "NumLib/Fem/InitShapeMatrices.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
-#include "NumLib/Function/Interpolation.h"
 #include "TESLocalAssembler.h"
 #include "TESReactionAdaptor.h"
 
diff --git a/ProcessLib/TES/TESLocalAssemblerInner-impl.h b/ProcessLib/TES/TESLocalAssemblerInner-impl.h
index 3e656a15174..f28e1b6a8fc 100644
--- a/ProcessLib/TES/TESLocalAssemblerInner-impl.h
+++ b/ProcessLib/TES/TESLocalAssemblerInner-impl.h
@@ -13,7 +13,7 @@
 
 #pragma once
 
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "TESLocalAssemblerInner-fwd.h"
 #include "TESOGS5MaterialModels.h"
 #include "TESReactionAdaptor.h"
diff --git a/ProcessLib/TH2M/TH2MFEM-impl.h b/ProcessLib/TH2M/TH2MFEM-impl.h
index dbd634fb9cc..9203a3d5326 100644
--- a/ProcessLib/TH2M/TH2MFEM-impl.h
+++ b/ProcessLib/TH2M/TH2MFEM-impl.h
@@ -19,7 +19,7 @@
 #include "MaterialLib/PhysicalConstant.h"
 #include "MathLib/EigenBlockMatrixView.h"
 #include "MathLib/KelvinVector.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "ProcessLib/Reflection/ReflectionSetIPData.h"
 #include "ProcessLib/Utils/SetOrGetIntegrationPointData.h"
 #include "TH2MProcessData.h"
diff --git a/ProcessLib/ThermalTwoPhaseFlowWithPP/ThermalTwoPhaseFlowWithPPLocalAssembler-impl.h b/ProcessLib/ThermalTwoPhaseFlowWithPP/ThermalTwoPhaseFlowWithPPLocalAssembler-impl.h
index 5a5aef378a1..278db2a722f 100644
--- a/ProcessLib/ThermalTwoPhaseFlowWithPP/ThermalTwoPhaseFlowWithPPLocalAssembler-impl.h
+++ b/ProcessLib/ThermalTwoPhaseFlowWithPP/ThermalTwoPhaseFlowWithPPLocalAssembler-impl.h
@@ -15,7 +15,7 @@
 #include "MaterialLib/MPL/Utils/FormEffectiveThermalConductivity.h"
 #include "MaterialLib/MPL/Utils/FormEigenTensor.h"
 #include "MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "ThermalTwoPhaseFlowWithPPLocalAssembler.h"
 #include "ThermalTwoPhaseFlowWithPPProcessData.h"
 
diff --git a/ProcessLib/ThermoHydroMechanics/ThermoHydroMechanicsFEM-impl.h b/ProcessLib/ThermoHydroMechanics/ThermoHydroMechanicsFEM-impl.h
index 6e7c01ff7e7..ae3e8597c75 100644
--- a/ProcessLib/ThermoHydroMechanics/ThermoHydroMechanicsFEM-impl.h
+++ b/ProcessLib/ThermoHydroMechanics/ThermoHydroMechanicsFEM-impl.h
@@ -20,7 +20,7 @@
 #include "MaterialLib/SolidModels/SelectSolidConstitutiveRelation.h"
 #include "MathLib/EigenBlockMatrixView.h"
 #include "MathLib/KelvinVector.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "NumLib/NumericalStability/AdvectionMatrixAssembler.h"
 #include "NumLib/NumericalStability/HydrodynamicDispersion.h"
 #include "ProcessLib/Utils/SetOrGetIntegrationPointData.h"
diff --git a/ProcessLib/ThermoRichardsFlow/ThermoRichardsFlowFEM-impl.h b/ProcessLib/ThermoRichardsFlow/ThermoRichardsFlowFEM-impl.h
index f73167171fe..58c8b2724fa 100644
--- a/ProcessLib/ThermoRichardsFlow/ThermoRichardsFlowFEM-impl.h
+++ b/ProcessLib/ThermoRichardsFlow/ThermoRichardsFlowFEM-impl.h
@@ -20,7 +20,7 @@
 #include "MaterialLib/MPL/Utils/GetLiquidThermalExpansivity.h"
 #include "MaterialLib/PhysicalConstant.h"
 #include "MaterialLib/SolidModels/SelectSolidConstitutiveRelation.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "ProcessLib/Utils/SetOrGetIntegrationPointData.h"
 #include "RigidElasticityModel.h"
 #include "UniaxialElasticityModel.h"
diff --git a/ProcessLib/ThermoRichardsMechanics/ThermoRichardsMechanicsFEM-impl.h b/ProcessLib/ThermoRichardsMechanics/ThermoRichardsMechanicsFEM-impl.h
index de3565e49b6..6a4b784b066 100644
--- a/ProcessLib/ThermoRichardsMechanics/ThermoRichardsMechanicsFEM-impl.h
+++ b/ProcessLib/ThermoRichardsMechanics/ThermoRichardsMechanicsFEM-impl.h
@@ -21,7 +21,7 @@
 #include "MaterialLib/MPL/Utils/GetLiquidThermalExpansivity.h"
 #include "MaterialLib/PhysicalConstant.h"
 #include "MathLib/KelvinVector.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "ProcessLib/Deformation/LinearBMatrix.h"
 #include "ProcessLib/Graph/Get.h"
 #include "ProcessLib/ThermoRichardsMechanics/ConstitutiveCommon/LiquidDensity.h"
diff --git a/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPLocalAssembler-impl.h b/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPLocalAssembler-impl.h
index fc4afc2c209..b86e2ce371c 100644
--- a/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPLocalAssembler-impl.h
+++ b/ProcessLib/TwoPhaseFlowWithPP/TwoPhaseFlowWithPPLocalAssembler-impl.h
@@ -33,7 +33,7 @@
 #include "MaterialLib/MPL/Medium.h"
 #include "MaterialLib/MPL/Utils/FormEigenTensor.h"
 #include "MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "TwoPhaseFlowWithPPProcessData.h"
 
 namespace ProcessLib
diff --git a/ProcessLib/TwoPhaseFlowWithPrho/TwoPhaseFlowWithPrhoLocalAssembler-impl.h b/ProcessLib/TwoPhaseFlowWithPrho/TwoPhaseFlowWithPrhoLocalAssembler-impl.h
index be526d8b67b..d4c517b020a 100644
--- a/ProcessLib/TwoPhaseFlowWithPrho/TwoPhaseFlowWithPrhoLocalAssembler-impl.h
+++ b/ProcessLib/TwoPhaseFlowWithPrho/TwoPhaseFlowWithPrhoLocalAssembler-impl.h
@@ -12,7 +12,7 @@
 
 #include "MaterialLib/MPL/Utils/FormEigenTensor.h"
 #include "MathLib/InterpolationAlgorithms/PiecewiseLinearInterpolation.h"
-#include "NumLib/Function/Interpolation.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "TwoPhaseFlowWithPrhoLocalAssembler.h"
 #include "TwoPhaseFlowWithPrhoProcessData.h"
 
diff --git a/Tests/NumLib/TestExtrapolation.cpp b/Tests/NumLib/TestExtrapolation.cpp
index 3fa03e8ee25..f1e94679206 100644
--- a/Tests/NumLib/TestExtrapolation.cpp
+++ b/Tests/NumLib/TestExtrapolation.cpp
@@ -21,8 +21,8 @@
 #include "NumLib/Extrapolation/LocalLinearLeastSquaresExtrapolator.h"
 #include "NumLib/Fem/FiniteElement/TemplateIsoparametric.h"
 #include "NumLib/Fem/InitShapeMatrices.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
-#include "NumLib/Function/Interpolation.h"
 #include "NumLib/NumericsConfig.h"
 #include "ProcessLib/Utils/CreateLocalAssemblers.h"
 #include "Tests/VectorUtils.h"
diff --git a/Tests/NumLib/TestFunctionInterpolation.cpp b/Tests/NumLib/TestFunctionInterpolation.cpp
index c1311dee9ba..8112a67f134 100644
--- a/Tests/NumLib/TestFunctionInterpolation.cpp
+++ b/Tests/NumLib/TestFunctionInterpolation.cpp
@@ -14,9 +14,9 @@
 #include "MeshLib/Elements/Element.h"
 #include "NumLib/Fem/FiniteElement/TemplateIsoparametric.h"
 #include "NumLib/Fem/Integration/GaussLegendreIntegrationPolicy.h"
+#include "NumLib/Fem/Interpolation.h"
 #include "NumLib/Fem/ShapeFunction/ShapeLine2.h"
 #include "NumLib/Fem/ShapeMatrixPolicy.h"
-#include "NumLib/Function/Interpolation.h"
 
 TEST(NumLibFunctionInterpolationTest, TwoVariablesTwoNodes)
 {