Merged IBPSA, issue1531_der_spliceFunction (#2681)

This avoids a potential overflow in the analytical derivative of the splice function
lbl-srg · Oct 16, 2021 · c779fa7 · c779fa7
1 parent 85dbc3e
commit c779fa7
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Showing 7 changed files with 96 additions and 78 deletions.
diff --git a/...ults/Dymola/Buildings_Utilities_Math_Functions_Examples_SpliceFunctionDerivativeCheck.txt b/...ults/Dymola/Buildings_Utilities_Math_Functions_Examples_SpliceFunctionDerivativeCheck.txt
diff --git a/...ources/Scripts/Dymola/Utilities/Math/Functions/Examples/SpliceFunctionDerivativeCheck.mos b/...ources/Scripts/Dymola/Utilities/Math/Functions/Examples/SpliceFunctionDerivativeCheck.mos
@@ -1,26 +1,5 @@
 simulateModel("Buildings.Utilities.Math.Functions.Examples.SpliceFunctionDerivativeCheck", startTime=-1, method="CVode", tolerance=1e-6, stopTime=1.0, resultFile="SpliceFunctionDerivativeCheck");
-removePlots();
-createPlot(id = 5,
- position = {45, 33, 639, 463},
- y = {"x", "y"},
- range = {(-1.0), 1, 2.5, 0},
- autoscale = true,
- autoerase = true,
- autoreplot = true,
- grid = true,
- color = true,
- filename = "SpliceFunctionDerivativeCheck.mat",
- leftTitleType = 1,
- bottomTitleType = 1);
-createPlot(id = 5,
- position = {45, 33, 639, 226},
- y = {"der(x)", "der(y)"},
- range = {(-1.0), 1, 2, (-2.0)},
- autoscale = true,
- autoerase = true,
- autoreplot = true,
- grid = true,
- color = true,
- subPlot = 2,
- leftTitleType = 1,
- bottomTitleType = 1);
+createPlot(id=5, position={61, 52, 878, 851}, y={"x", "y"}, range={-1.0, 1.0, -20.0, 10.0}, grid=true, colors={{28,108,200}, {238,46,47}}, timeUnit="s", displayUnits={"s3", ""});
+createPlot(id=5, position={61, 52, 878, 851}, y={"der(x)", "der(y)"}, range={-1.0, 1.0, -50.0, 100.0}, grid=true, subPlot=102, colors={{28,108,200}, {238,46,47}}, timeUnit="s", displayUnits={"s2", ""});
+createPlot(id=5, position={61, 52, 878, 851}, y={"d2y"}, range={-1.0, 1.0, -500.0, 500.0}, grid=true, subPlot=103, colors={{28,108,200}}, timeUnit="s");
+createPlot(id=5, position={61, 52, 878, 851}, y={"d3y"}, range={-1.0, 1.0, -10000.0, 5000.0}, grid=true, subPlot=104, colors={{28,108,200}}, timeUnit="s");
diff --git a/...compareVars/Buildings.Utilities.Math.Functions.Examples.SpliceFunctionDerivativeCheck.mos b/...compareVars/Buildings.Utilities.Math.Functions.Examples.SpliceFunctionDerivativeCheck.mos
@@ -3,5 +3,7 @@ compareVars :=
     "x",
     "y",
     "der(x)",
-    "der(y)"
+    "der(y)",
+    "d2y",
+    "d3y"
   };
diff --git a/Buildings/Utilities/Math/Functions/BaseClasses/der_spliceFunction.mo b/Buildings/Utilities/Math/Functions/BaseClasses/der_spliceFunction.mo
@@ -1,38 +1,41 @@
 within Buildings.Utilities.Math.Functions.BaseClasses;
 function der_spliceFunction "Derivative of splice function"
   extends Modelica.Icons.Function;
-    input Real pos;
-    input Real neg;
-    input Real x;
-    input Real deltax=1;
-    input Real dpos;
-    input Real dneg;
-    input Real dx;
-    input Real ddeltax=0;
-    output Real out;
+  input Real pos;
+  input Real neg;
+  input Real x;
+  input Real deltax=1;
+  input Real dpos;
+  input Real dneg;
+  input Real dx;
+  input Real ddeltax=0;
+  output Real out;
 protected
-    Real scaledX;
-    Real scaledX1;
-    Real dscaledX1;
-    Real y;
-    constant Real asin1 = Modelica.Math.asin(1);
+  Real scaledX1 "x scaled to -1 ... 1 interval";
+  Real scaledXp "x scaled to -pi/2 ... pi/2 interval";
+  Real scaledXt "x scaled to -inf ... inf interval";
+  Real dscaledX1;
+  Real y;
 algorithm
-    scaledX1 := x/deltax;
-    if scaledX1 <= -0.99999999999 then
-      out := dneg;
-    elseif scaledX1 >= 0.9999999999 then
-      out := dpos;
-    else
-      scaledX := scaledX1*asin1;
-      dscaledX1 := (dx - scaledX1*ddeltax)/deltax;
-      y := (Modelica.Math.tanh(Modelica.Math.tan(scaledX)) + 1)/2;
-      out := dpos*y + (1 - y)*dneg;
-      out := out + (pos - neg)*dscaledX1*asin1/2/(
-        Modelica.Math.cosh(Modelica.Math.tan(scaledX))*Modelica.Math.cos(
-        scaledX))^2;
-    end if;
+  scaledX1 := x/deltax;
+  if scaledX1 <= -0.9999999999 then
+    y := 0.0;
+  elseif scaledX1 >= 0.9999999999 then
+    y := 1.0;
+  else
+    scaledXp := scaledX1*0.5*Modelica.Constants.pi;
+    scaledXt := Modelica.Math.tan(scaledXp);
+    y := 0.5*Modelica.Math.tanh(scaledXt) + 0.5;
+  end if;
+  out := dpos*y + (1 - y)*dneg;
+
+  if (abs(scaledX1) < 1) then
+    dscaledX1 := (dx - scaledX1*ddeltax)/deltax;
+    out := out + (pos - neg)*dscaledX1*0.25*Modelica.Constants.pi*(1 - Modelica.Math.tanh(scaledXt)^2)*(scaledXt^2 + 1);
+  end if;
 
 annotation (
+  smoothOrder=2,
 Documentation(
 info="<html>
 <p>
@@ -44,6 +47,12 @@ Buildings.Utilities.Math.Functions.spliceFunction</a>.
 revisions="<html>
 <ul>
 <li>
+October 13, 2021, by Michael Wetter:<br/>
+Changed implementation to not use <code>cosh</code> which overflows around <i>800</i>.<br/>
+This is for
+<a href=\"https://github.com/ibpsa/modelica-ibpsa/issues/1531\">IBPSA, issue 1531</a>.
+</li>
+<li>
 May 10, 2013, by Michael Wetter:<br/>
 Reformulated implementation to avoid unrequired computations.
 </li>

diff --git a/Buildings/Utilities/Math/Functions/Examples/SpliceFunctionDerivativeCheck.mo b/Buildings/Utilities/Math/Functions/Examples/SpliceFunctionDerivativeCheck.mo
@@ -11,6 +11,10 @@ model SpliceFunctionDerivativeCheck
 
   Real err "Error";
 
+  Real d1y "First derivative";
+  Real d2y "Second derivative";
+  Real d3y "Third derivative";
+
 initial equation
    y=y_comp;
 equation
@@ -28,7 +32,14 @@ equation
   err = y-y_comp;
   assert(abs(err) < 1E-2, "Model has an error");
 
- annotation(experiment(StartTime=-1, Tolerance=1e-6, StopTime=1.0),
+  d1y = der(y);
+  d2y = der(d1y);
+  d3y = der(d2y);
+
+ annotation(experiment(
+      StartTime=-1,
+      StopTime=1,
+      Tolerance=1e-06),
 __Dymola_Commands(file="modelica://Buildings/Resources/Scripts/Dymola/Utilities/Math/Functions/Examples/SpliceFunctionDerivativeCheck.mos"
         "Simulate and plot"),
     Documentation(info="<html>
@@ -40,6 +51,12 @@ is not correct, the model will stop with an assert statement.
 </html>", revisions="<html>
 <ul>
 <li>
+October 13, 2021, by Michael Wetter:<br/>
+Added new output for higher order derivatives.<br/>
+This is for
+<a href=\"https://github.com/ibpsa/modelica-ibpsa/issues/1531\">IBPSA, issue 1531</a>.
+</li>
+<li>
 August 17, 2015 by Michael Wetter:<br/>
 Updated regression test to have slope that is different from one.
 This is for

diff --git a/Buildings/Utilities/Math/Functions/spliceFunction.mo b/Buildings/Utilities/Math/Functions/spliceFunction.mo
@@ -22,7 +22,7 @@ algorithm
     end if;
 
     annotation (
-smoothOrder=1,
+smoothOrder=3,
 derivative=BaseClasses.der_spliceFunction,
 Documentation(info="<html>
 <p>

diff --git a/Buildings/package.mo b/Buildings/package.mo
@@ -320,17 +320,13 @@ have been <b style=\"color:blue\">improved</b> in a
                        This new version also outputs this altitude and the latitude of the location on the weather data bus.<br/>
                        This is for <a href=\"https://github.com/ibpsa/modelica-ibpsa/issues/1477\">IBPSA, issue #1477</a>.
     </td>
-<tr><td colspan=\"2\"><b>Buildings.Fluid.Actuators</b>
+<tr><td colspan=\"2\"><b>Buildings.Controls.OBC</b>
     </td>
 </tr>
-<tr><td valign=\"top\">Buildings.Fluid.Movers.FlowControlled_dp<br/>
-                       Buildings.Fluid.Movers.FlowControlled_m_flow<br/>
-                       Buildings.Fluid.Movers.SpeedControlled_Nrpm<br/>
-                       Buildings.Fluid.Movers.SpeedControlled_y
+<tr><td valign=\"top\">Buildings.Controls.OBC.ASHRAE.G36_PR1.Generic.SetPoints.GroupStatus
     </td>
-    <td valign=\"top\">Changed implementation of the filter.
-                       The new implementation uses a simpler model.<br/>
-                       This is for <a href=\"https://github.com/ibpsa/modelica-ibpsa/issues/1498\">IBPSA #1498</a>.
+    <td valign=\"top\">Added filters to select which zones are used in group.<br/>
+                       This is for <a href=\"https://github.com/lbl-srg/modelica-buildings/issues/2544\">issue 2544</a>.
     </td>
 </tr>
 <tr><td colspan=\"2\"><b>Buildings.Examples</b>
@@ -360,6 +356,19 @@ have been <b style=\"color:blue\">improved</b> in a
                        This is for <a href=\"https://github.com/lbl-srg/modelica-buildings/issues/2624\">issue #2624</a>.
     </td>
 </tr>
+<tr><td colspan=\"2\"><b>Buildings.Fluid.Actuators</b>
+    </td>
+</tr>
+<tr><td valign=\"top\">Buildings.Fluid.Movers.FlowControlled_dp<br/>
+                       Buildings.Fluid.Movers.FlowControlled_m_flow<br/>
+                       Buildings.Fluid.Movers.SpeedControlled_Nrpm<br/>
+                       Buildings.Fluid.Movers.SpeedControlled_y
+    </td>
+    <td valign=\"top\">Changed implementation of the filter.
+                       The new implementation uses a simpler model.<br/>
+                       This is for <a href=\"https://github.com/ibpsa/modelica-ibpsa/issues/1498\">IBPSA #1498</a>.
+    </td>
+</tr>
 <tr><td colspan=\"2\"><b>Buildings.Fluid.FMI</b>
     </td>
 </tr>
@@ -391,13 +400,13 @@ have been <b style=\"color:blue\">improved</b> in a
                        This is for <a href=\"https://github.com/ibpsa/modelica-ibpsa/pull/1516\">IBPSA #1516</a>.
     </td>
 </tr>
-<tr><td colspan=\"2\"><b>Buildings.Controls.OBC</b>
+<tr><td colspan=\"2\"><b>Buildings.Utilities.Math</b>
     </td>
 </tr>
-<tr><td valign=\"top\">Buildings.Controls.OBC.ASHRAE.G36_PR1.Generic.SetPoints.GroupStatus
+<tr><td valign=\"top\">Buildings.Utilities.Math.Functions.BaseClasses.der_spliceFunction
     </td>
-    <td valign=\"top\">Add filters to select which zones are used in group.<br/>
-                       This is for <a href=\"https://github.com/lbl-srg/modelica-buildings/issues/2544\">issue 2544</a>.
+    <td valign=\"top\">Reimplemented function to avoid a potential overflow caused by the <code>cosh</code> function.<br/>
+                       This is for <a href=\"https://github.com/ibpsa/modelica-ibpsa/pull/1531\">IBPSA #1531</a>.
     </td>
 </tr>
 </table>