Modelica中的条件组件(Conditional Components in Modelica)

 我想用条件表达式减少超过300000个方程的大型通用模型，这样只剩下相关的部分。 为了说明问题，我有以下最小模型： 
 
model Test
  parameter Boolean level1=true;
  parameter Boolean level2=false;
  Integer x=1 if level1;
  Integer y=2 if level2;
  Integer z;
equation
  if level1 and level2 then
    z = x+y;
  elseif level1 then
    z = x;
  elseif level2 then
    z = y;
  else
    z=0;
  end if;
end Test;
 
 此模型在Dymola中不起作用，并显示以下错误消息： 
 
 
 
 未声明的变量：y因为有条件地删除了y的声明 
 
 
 在OpenModelica中，模型有效。 所以我的问题是，这个Model Modelica是否合规？ 在Modelica 3.4规范第4.4.5节中，我没有找到任何会使该模型无效的内容。 
 
 谢谢您的帮助。 

I want with conditional expressions reduce large general models with over 300000 equations so that only a relevant part remains. To illustrate the problem I have the following minimal model:
 
model Test
  parameter Boolean level1=true;
  parameter Boolean level2=false;
  Integer x=1 if level1;
  Integer y=2 if level2;
  Integer z;
equation
  if level1 and level2 then
    z = x+y;
  elseif level1 then
    z = x;
  elseif level2 then
    z = y;
  else
    z=0;
  end if;
end Test;
 
This model does not work in Dymola, with the error message:
 
 
 
Undeclared variables: y since the declaration of y was conditionally removed
 
 
In OpenModelica the model works. So my question is, is this Model Modelica compliant? In the Modelica 3.4 specification section 4.4.5 I did not find anything that would invalidate this model.
 
Thanks for the help.

原文：https://stackoverflow.com/questions/48662090