t-sommer · Oct 19, 2026 · Sep 30, 2026 · Oct 19, 2026 · Oct 19, 2026
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
@@ -21,12 +21,9 @@ jobs:
           - name: linux64
             image: ubuntu-22.04
             cmake-args: -G "Unix Makefiles"
-          - name: darwin64
-            image: macos-13
-            cmake-args: -G "Unix Makefiles" -D CMAKE_OSX_ARCHITECTURES=x86_64
     runs-on: ${{ matrix.image }}
     steps:
-    - uses: actions/checkout@v4.1.7
+    - uses: actions/checkout@v7
       with:
         submodules: recursive
     - run: |
@@ -39,7 +36,7 @@ jobs:
         cmake ${{ matrix.cmake-args }} -B ${{ matrix.name }} .
         cmake --build ${{ matrix.name }} --config Release
         ctest --test-dir ${{ matrix.name }} --build-config Release
-    - uses: actions/upload-artifact@v4.4.0
+    - uses: actions/upload-artifact@v7
       with:
         name: ${{ matrix.name }}
         path: SDF
@@ -48,25 +45,21 @@ jobs:
     runs-on: ubuntu-22.04
     needs: [build]
     steps:
-    - uses: actions/checkout@v4.1.7
-    - uses: actions/download-artifact@v4.1.8
+    - uses: actions/checkout@v7
+    - uses: actions/download-artifact@v8
       with:
         name: win64
         path: SDF
-    - uses: actions/download-artifact@v4.1.8
+    - uses: actions/download-artifact@v8
       with:
         name: win32
         path: SDF
-    - uses: actions/download-artifact@v4.1.8
+    - uses: actions/download-artifact@v8
       with:
         name: linux64
         path: SDF
-    - uses: actions/download-artifact@v4.1.8
-      with:
-        name: darwin64
-        path: SDF
     - run: find -type f -name .gitignore -delete
-    - uses: actions/upload-artifact@v4.4.0
+    - uses: actions/upload-artifact@v7
       with:
         name: SDF-Modelica
         path: |

diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required (VERSION 3.2)
+cmake_minimum_required (VERSION 3.20)
 
 set (CMAKE_CXX_STANDARD 14)
 
@@ -99,3 +99,15 @@ set_property(TARGET ModelicaSDF_Test PROPERTY VS_DEBUGGER_WORKING_DIRECTORY "${C
 enable_testing()
 
 add_test(NAME ModelicaSDF_Test COMMAND $<TARGET_FILE:ModelicaSDF_Test> WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/C/tests")
+
+add_library(NDTable SHARED
+  SDF/Resources/C-Sources/NDTable.h
+  SDF/Resources/C-Sources/ModelicaNDTable.c
+  SDF/Resources/C-Sources/NDTable.h
+  ThirdParty/ModelicaUtilities.h
+  ThirdParty/ModelicaUtilities.c
+)
+
+target_include_directories(NDTable PUBLIC
+	ThirdParty
+)
diff --git a/SDF/Examples/InterpolationMethods.mo b/SDF/Examples/InterpolationMethods.mo
@@ -1,39 +1,49 @@
 within SDF.Examples;
-model InterpolationMethods "Interpolate a sampled signal using different interpolation methods"
+model InterpolationMethods "Interpolate a sampled signal using different interpolation and extrapolation methods"
   extends Modelica.Icons.Example;
 
-  parameter Real x[:] = linspace(0,2,6) * Modelica.Constants.pi;
+  parameter Real x[:] = linspace(0, 2, 6) * Modelica.Constants.pi;
   parameter Real y[size(x, 1)] = Modelica.Math.sin(x);
   parameter Real data[:] = cat(1, {1}, {size(x, 1)}, x, y);
 
   parameter String filename = Modelica.Utilities.Files.loadResource("modelica://SDF/Resources/Data/Examples/sine.sdf");
   parameter String dataset = "/y";
 
-  NDTable linear(
+  Modelica.Blocks.Sources.Ramp ramp(
+    duration=1,
+    offset=-1,
+    height=8.3)
+    annotation (Placement(transformation(extent={{-80,-30},{-60,-10}})));
+
+  NDTable hold(
     nin=1,
     readFromFile=false,
     data=data,
-    interpMethod=SDF.Types.InterpolationMethod.Linear,
+    interpMethod=SDF.Types.InterpolationMethod.Hold,
     extrapMethod=SDF.Types.ExtrapolationMethod.Linear,
     filename=filename,
     dataset=dataset)
-    annotation (Placement(transformation(extent={{-10,10},{10,30}})));
+    annotation (Placement(transformation(extent={{-40,40},{-20,60}})));
 
-  Modelica.Blocks.Sources.Ramp ramp(
-    duration=1,
-    offset=-1,
-    height=8.3)
-    annotation (Placement(transformation(extent={{-70,-10},{-50,10}})));
+  NDTable nearest(
+    nin=1,
+    readFromFile=false,
+    data=data,
+    interpMethod=SDF.Types.InterpolationMethod.Nearest,
+    extrapMethod=SDF.Types.ExtrapolationMethod.Linear,
+    filename=filename,
+    dataset=dataset)
+    annotation (Placement(transformation(extent={{0,40},{20,60}})));
 
-  NDTable hold(
+  NDTable linear(
     nin=1,
     readFromFile=false,
     data=data,
-    interpMethod=SDF.Types.InterpolationMethod.Hold,
-    extrapMethod=SDF.Types.ExtrapolationMethod.Hold,
+    interpMethod=SDF.Types.InterpolationMethod.Linear,
+    extrapMethod=SDF.Types.ExtrapolationMethod.Linear,
     filename=filename,
     dataset=dataset)
-    annotation (Placement(transformation(extent={{-10,90},{10,110}})));
+    annotation (Placement(transformation(extent={{40,40},{60,60}})));
 
   NDTable akima(
     nin=1,
@@ -43,56 +53,75 @@ model InterpolationMethods "Interpolate a sampled signal using different interpo
     extrapMethod=SDF.Types.ExtrapolationMethod.Linear,
     filename=filename,
     dataset=dataset)
-    annotation (Placement(transformation(extent={{-10,-30},{10,-10}})));
+    annotation (Placement(transformation(extent={{-40,0},{-20,20}})));
 
-  NDTable nearest(
+  NDTable fritsch_butland(
     nin=1,
     readFromFile=false,
     data=data,
-    interpMethod=SDF.Types.InterpolationMethod.Nearest,
-    extrapMethod=SDF.Types.ExtrapolationMethod.Hold,
+    interpMethod=SDF.Types.InterpolationMethod.FritschButland,
+    extrapMethod=SDF.Types.ExtrapolationMethod.Linear,
     filename=filename,
     dataset=dataset)
-    annotation (Placement(transformation(extent={{-10,50},{10,70}})));
+    annotation (Placement(transformation(extent={{0,0},{20,20}})));
 
-  NDTable fritsch_butland(
+  NDTable steffen(
     nin=1,
     readFromFile=false,
     data=data,
+    interpMethod=SDF.Types.InterpolationMethod.Steffen,
     extrapMethod=SDF.Types.ExtrapolationMethod.Linear,
-    interpMethod=SDF.Types.InterpolationMethod.FritschButland,
     filename=filename,
     dataset=dataset)
-    annotation (Placement(transformation(extent={{-10,-70},{10,-50}})));
+    annotation (Placement(transformation(extent={{40,0},{60,20}})));
 
-  NDTable steffen(
+  NDTable extrap_hold(
+    nin=1,
+    readFromFile=false,
+    data=data,
+    interpMethod=SDF.Types.InterpolationMethod.Linear,
+    extrapMethod=SDF.Types.ExtrapolationMethod.Hold,
+    filename=filename,
+    dataset=dataset)
+    annotation (Placement(transformation(extent={{-20,-60},{0,-40}})));
+
+  NDTable extrap_linear(
     nin=1,
     readFromFile=false,
     data=data,
+    interpMethod=SDF.Types.InterpolationMethod.Linear,
     extrapMethod=SDF.Types.ExtrapolationMethod.Linear,
-    interpMethod=SDF.Types.InterpolationMethod.Steffen,
     filename=filename,
     dataset=dataset)
-    annotation (Placement(transformation(extent={{-10,-110},{10,-90}})));
+    annotation (Placement(transformation(extent={{20,-60},{40,-40}})));
 
 equation
-  connect(ramp.y, hold.u[1]) annotation (Line(points={{-49,0},{-30,0},{-30,100},
-          {-12,100}},
-                    color={0,0,127}));
-  connect(ramp.y, akima.u[1]) annotation (Line(points={{-49,0},{-30,0},{-30,-20},
-          {-12,-20}}, color={0,0,127}));
-  connect(ramp.y, linear.u[1]) annotation (Line(points={{-49,0},{-30,0},{-30,20},
-          {-12,20}},                  color={0,0,127}));
-  connect(ramp.y, nearest.u[1]) annotation (Line(points={{-49,0},{-30,0},{-30,
-          60},{-12,60}},
+  connect(ramp.y, hold.u[1]) annotation (Line(points={{-59,-20},{-50,-20},{-50,
+          50},{-42,50}},
                      color={0,0,127}));
-  connect(ramp.y, fritsch_butland.u[1]) annotation (Line(points={{-49,0},{-30,0},
-          {-30,-60},{-12,-60}}, color={0,0,127}));
-  connect(ramp.y, steffen.u[1]) annotation (Line(points={{-49,0},{-30,0},{-30,
-          -100},{-12,-100}},
-                      color={0,0,127}));
+  connect(akima.u[1], ramp.y) annotation (Line(points={{-42,10},{-50,10},{-50,
+          -20},{-59,-20}},
+                    color={0,0,127}));
+  connect(nearest.u[1], ramp.y) annotation (Line(points={{-2,50},{-10,50},{-10,
+          -20},{-59,-20}},
+                       color={0,0,127}));
+  connect(fritsch_butland.u[1], ramp.y) annotation (Line(points={{-2,10},{-10,
+          10},{-10,-20},{-59,-20}},
+                                color={0,0,127}));
+  connect(linear.u[1], ramp.y) annotation (Line(points={{38,50},{30,50},{30,-20},
+          {-59,-20}},
+                    color={0,0,127}));
+  connect(steffen.u[1], ramp.y) annotation (Line(points={{38,10},{30,10},{30,
+          -20},{-59,-20}},
+                    color={0,0,127}));
+  connect(extrap_hold.u[1], ramp.y) annotation (Line(points={{-22,-50},{-30,-50},
+          {-30,-20},{-59,-20}},
+                            color={0,0,127}));
+  connect(extrap_linear.u[1], ramp.y) annotation (Line(points={{18,-50},{10,-50},
+          {10,-20},{-59,-20}},
+                           color={0,0,127}));
   annotation (
-    Diagram(coordinateSystem(preserveAspectRatio=false, extent={{-100,-120},{
-            100,120}})),
-    Icon(coordinateSystem(extent={{-100,-80},{100,100}})));
+    Diagram(coordinateSystem(preserveAspectRatio=false, extent={{-100,-100},{
+            100,100}})),
+    Icon(coordinateSystem(extent={{-100,-100},{100,120}})));
 end InterpolationMethods;
diff --git a/SDF/NDTable.mo b/SDF/NDTable.mo
@@ -12,10 +12,22 @@ parameter SDF.Types.InterpolationMethod interpMethod=SDF.Types.InterpolationMeth
     "Interpolation method";
 parameter SDF.Types.ExtrapolationMethod extrapMethod=SDF.Types.ExtrapolationMethod.None
     "Extrapolation method";
+parameter Boolean enableDy_du=false "Enable partial derivative output dy_du"
+    annotation(Evaluate=true);
 
- parameter Real data[:] = { 0}   "Table data (as returned by readTableData())" annotation(Dialog(enable=not readFromFile), Evaluate=true);
+parameter Real data[:] = { 0}   "Table data (as returned by readTableData())" annotation(Dialog(enable=not readFromFile), Evaluate=true);
+
+Modelica.Blocks.Interfaces.RealOutput dy_du[nin] if enableDy_du
+    "Partial derivatives of y with respect to each input u[i]"
+    annotation (Placement(
+      transformation(extent={{-10,-10},{10,10}},
+        rotation=0,
+        origin={110,-60}),
+      visible=enableDy_du));
 
 protected
+  Modelica.Blocks.Interfaces.RealInput local_dy_du[nin] annotation(HideResult=true);
+
   function evaluate
     input SDF.Types.ExternalNDTable table;
     input Real[:] params;
@@ -25,21 +37,73 @@ protected
     external "C" value = ModelicaNDTable_evaluate(table, size(params, 1), params, interpMethod, extrapMethod) annotation (
       Include="#include <ModelicaNDTable.c>",
       IncludeDirectory="modelica://SDF/Resources/C-Sources");
+    annotation(
+      derivative(zeroDerivative = table,
+               zeroDerivative = interpMethod,
+               zeroDerivative = extrapMethod) = evaluate_der);
   end evaluate;
 
+  function evaluate_der
+    input SDF.Types.ExternalNDTable table;
+    input Real[:] params;
+    input SDF.Types.InterpolationMethod interpMethod;
+    input SDF.Types.ExtrapolationMethod extrapMethod;
+    input Real[size(params, 1)] der_params;
+    output Real der_value;
+    external "C" der_value = ModelicaNDTable_evaluate_derivative(
+      table,
+      size(params, 1),
+      params,
+      interpMethod,
+      extrapMethod,
+      der_params)
+    annotation (
+      Include="#include <ModelicaNDTable.c>",
+      IncludeDirectory="modelica://SDF/Resources/C-Sources");
+  end evaluate_der;
+
+  function evaluatePartialDerivatives
+    input SDF.Types.ExternalNDTable table;
+    input Real[:] params;
+    input SDF.Types.InterpolationMethod interpMethod;
+    input SDF.Types.ExtrapolationMethod extrapMethod;
+    output Real derivatives[size(params, 1)];
+    external "C" ModelicaNDTable_evaluate_partial_derivatives(
+      table,
+      size(params, 1),
+      params,
+      interpMethod,
+      extrapMethod,
+      derivatives) annotation (
+      Include="#include <ModelicaNDTable.c>",
+      IncludeDirectory="modelica://SDF/Resources/C-Sources");
+  end evaluatePartialDerivatives;
+
   SDF.Types.ExternalNDTable externalTable=SDF.Types.ExternalNDTable(nin, if readFromFile then SDF.Functions.readTableData(
         Modelica.Utilities.Files.loadResource(filename),
         dataset,
         dataUnit,
         scaleUnits) else data);
 
 equation
-                 y = evaluate(
+  y = evaluate(
     externalTable,
     u,
     interpMethod,
     extrapMethod);
 
+  if enableDy_du then
+    connect(dy_du, local_dy_du);
+    local_dy_du = evaluatePartialDerivatives(
+      externalTable,
+      u,
+      interpMethod,
+      extrapMethod);
+  else
+    local_dy_du = zeros(nin);
+  end if;
+
+
   annotation (Documentation(info="<html>
 <body>
 <p>The <strong>NDTable</strong> block is a multi-dimensional lookup-table (up to 32 dimensions) that supports various inter- and extrapolation methods.</p>