Avoid chattering in a block that finds the index of the highest value in a vector

Modelica Newbie trying to build a block that identifies the highest value of a set of real values (vector).

I tried two versions - one which would just give me the index of the highest value and one which would switch the value of a corresponding boolean vector.

Both failed. For certain high input values the model worked (almost), but most of the time I get an error saying: "Chattering detected around time 0.0277777777839..0.0277777778544 (100 state events in a row with a total time delta less than the step size 0.02). This can be a performance bottleneck. Use -lv LOG_EVENTS for more information. The zero-crossing was: indexMaxBool1.temp > indexMaxBool1.tempMax"

I googled error messages involving chattering and found answers telling to replace the IF-statement by WHEN. I only am affraid, that the latter won't raise the calculation as often as needed (only once??? Does it need a reset?).

I would appreciate getting some hints on how to avoid that chattering.

Here are my models so far:

Block to get the index of the highest value:

block IndexMax
  extends Modelica.Blocks.Icons.Block;
  parameter Integer nin=1 "Number of inputs";
  Modelica.Blocks.Interfaces.RealInput v[nin];
  Modelica.Blocks.Interfaces.IntegerOutput index;

    protected
      Real tempMax;
      Real temp;

algorithm
   if size(v,1)>1 then
     tempMax := v[1];
     index := 1;

     for i in 2:size(v,1) loop
       temp := v[i];
       if temp > tempMax then
        tempMax := temp;
        index := i;
       end if;
     end for;
  else
    index :=0;
  end if;

end IndexMax;

Block to get a vector of boolean values, with one switched on at the index of the highest input:

block IndexMaxBool
  extends Modelica.Blocks.Icons.Block;
  parameter Integer nin = 1 "Number of inputs";
  Modelica.Blocks.Interfaces.RealInput v[nin];
  Modelica.Blocks.Interfaces.BooleanOutput bool[nin];
protected
  Real tempMax;
  Real temp;
  Integer index;
algorithm
  if size(v, 1) > 1 then
    for i in 1:size(v,1) loop
      bool[i] := false;
    end for;
    tempMax := v[1];
    index := 1;

    for i in 2:size(v, 1) loop
      temp := v[i];
      if temp > tempMax then
        tempMax := temp;
        index := i;
      end if;
    end for;
  else
    index := 0;
  end if;
  if index > 0 then
    bool[index]:=true;
  end if;
end IndexMaxBool;

The test Models:

model testMax2
    Modelica.Blocks.Sources.RealExpression realExpression1(y = 1);
    FlowsAndStreams.BDSCalc.IndexMaxBool indexMaxBool1(nin = 3);
    Modelica.Blocks.Interfaces.BooleanOutput y;
    Modelica.Blocks.Interfaces.BooleanOutput y1;
    Modelica.Blocks.Interfaces.BooleanOutput y2;
    Modelica.Blocks.Sources.Sine sine1(amplitude = 2, freqHz = 1, phase = 0.785398);
    Modelica.Blocks.Sources.Sine sine2(amplitude = 2, freqHz = 3);
    equation
      connect(sine1.y, indexMaxBool1.v[2]);
      connect(sine2.y, indexMaxBool1.v[3]);
      connect(indexMaxBool1.bool[3], y2);
      connect(indexMaxBool1.bool[1], y);
      connect(indexMaxBool1.bool[2], y1);
      connect(realExpression1.y, indexMaxBool1.v[1]);
end testMax2;

and:

model testMax
    FlowsAndStreams.BDSCalc.IndexMax indexMax1(nin = 3);
    Modelica.Blocks.Sources.RealExpression realExpression1(y = 1);
    Modelica.Blocks.Sources.RealExpression realExpression2(y = 10);
    Modelica.Blocks.Sources.RealExpression realExpression3(y = 3);
    Modelica.Blocks.Interfaces.IntegerOutput y;
    equation
      connect(realExpression3.y, indexMax1.v[3]) annotation(
        Line(points = {{-69, -40}, {-8, -40}, {-8, 0}}, color = {0, 0, 127}));
      connect(realExpression2.y, indexMax1.v[2]) annotation(
        Line(points = {{-69, 0}, {-8, 0}}, color = {0, 0, 127}));
      connect(realExpression1.y, indexMax1.v[1]) annotation(
        Line(points = {{-69, 30}, {-10, 30}, {-10, 0}, {-8, 0}}, color = {0, 0, 127}));
      connect(indexMax1.index, y) annotation(
        Line(points = {{10, 0}, {50, 0}}, color = {255, 127, 0}));
end testMax;