id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
5834	Automatic sum using inner outer keywords behaves diferently in new frontend	libor.kudela@…	Francesco Casella	"I developed a method for summing(collecting) set of Real values from across instances into one global instance.

Please consider this Modelica code as MWE:

{{{
#!div style=""font-size: 90%""
Example package:
  {{{#!modelica
  package global_sum_test

  connector Sum_port
    flow Real a;
    flow Real b;
  end Sum_port;

  model Global
    Sum_port sum;
    annotation(defaultComponentName = ""global"");
  end Global;
  
  model Sum_adder
    outer Global global;
    outer Sum_port sum; //consider having or not having the outer keyword in front of this declaration
    Real a;
    Real b;
  equation
    sum.a = a;
    sum.b = b;
    connect(sum, global.sum);
  end Sum_adder;

  model Local
    parameter Real a = 0.5;
    parameter Real b = 1.0;
    Sum_adder sum_adder(a=a,b=b);
  end Local;
 
  model Local_nested
    parameter Real a = 0.5;
    parameter Real b = 1.0;
    Sum_adder sum_adder(a=a,b=b);
    Local local;
  end Local_nested;

  model test_model
    inner global_sum_test.Global global;
    Local local;
    Local_nested local_nested;
  end test_model;

end global_sum_test;
  }}}

'''Old frontend Instantiating global_sum_test.test_model:'''
 
{{{
#!div style=""font-size: 100%""
""outer"" keyword not present:
  {{{#!modelica
  class global_sum_test.test_model
  Real global.sum.a;
  Real global.sum.b;
  parameter Real local.a = 0.5;
  parameter Real local.b = 1.0;
  Real local.sum_adder.sum.a;
  Real local.sum_adder.sum.b;
  Real local.sum_adder.a = local.a;
  Real local.sum_adder.b = local.b;
  parameter Real local_nested.a = 0.5;
  parameter Real local_nested.b = 1.0;
  Real local_nested.sum_adder.sum.a;
  Real local_nested.sum_adder.sum.b;
  Real local_nested.sum_adder.a = local_nested.a;
  Real local_nested.sum_adder.b = local_nested.b;
  parameter Real local_nested.local.a = 0.5;
  parameter Real local_nested.local.b = 1.0;
  Real local_nested.local.sum_adder.sum.a;
  Real local_nested.local.sum_adder.sum.b;
  Real local_nested.local.sum_adder.a = local_nested.local.a;
  Real local_nested.local.sum_adder.b = local_nested.local.b;
equation
  local.sum_adder.sum.a = local.sum_adder.a;
  local.sum_adder.sum.b = local.sum_adder.b;
  local_nested.sum_adder.sum.a = local_nested.sum_adder.a;
  local_nested.sum_adder.sum.b = local_nested.sum_adder.b;
  local_nested.local.sum_adder.sum.a = local_nested.local.sum_adder.a;
  local_nested.local.sum_adder.sum.b = local_nested.local.sum_adder.b;
  global.sum.b + (-local.sum_adder.sum.b) + (-local_nested.local.sum_adder.sum.b) + (-local_nested.sum_adder.sum.b) = 0.0;
  global.sum.a + (-local.sum_adder.sum.a) + (-local_nested.local.sum_adder.sum.a) + (-local_nested.sum_adder.sum.a) = 0.0;
  local.sum_adder.sum.b = 0.0;
  local.sum_adder.sum.a = 0.0;
  local_nested.local.sum_adder.sum.b = 0.0;
  local_nested.local.sum_adder.sum.a = 0.0;
  local_nested.sum_adder.sum.b = 0.0;
  local_nested.sum_adder.sum.a = 0.0;
end global_sum_test.test_model;
  }}}
}}}

which obviously does not work since the system is overdetermined by additional 6 equations generated at the end. 

So I added the ""outer"" keyword in front of the commented declaration. It complains but compiles and everything is working.

[5] 22:02:03 Translation Error
[global_sum_test: 21:5-21:29]: The language feature Connections where both connectors are outer references is not supported. Suggested workaround: No suggestion

{{{
#!div style=""font-size: 100%""
""outer"" keyword is present:
  {{{#!modelica
  class global_sum_test.test_model
  Real global.sum.a;
  Real global.sum.b;
  parameter Real local.a = 0.5;
  parameter Real local.b = 1.0;
  Real local.sum_adder.sum.a;
  Real local.sum_adder.sum.b;
  Real local.sum_adder.a = local.a;
  Real local.sum_adder.b = local.b;
  parameter Real local_nested.a = 0.5;
  parameter Real local_nested.b = 1.0;
  Real local_nested.sum_adder.sum.a;
  Real local_nested.sum_adder.sum.b;
  Real local_nested.sum_adder.a = local_nested.a;
  Real local_nested.sum_adder.b = local_nested.b;
  parameter Real local_nested.local.a = 0.5;
  parameter Real local_nested.local.b = 1.0;
  Real local_nested.local.sum_adder.sum.a;
  Real local_nested.local.sum_adder.sum.b;
  Real local_nested.local.sum_adder.a = local_nested.local.a;
  Real local_nested.local.sum_adder.b = local_nested.local.b;
equation
  local.sum_adder.sum.a = local.sum_adder.a;
  local.sum_adder.sum.b = local.sum_adder.b;
  local_nested.sum_adder.sum.a = local_nested.sum_adder.a;
  local_nested.sum_adder.sum.b = local_nested.sum_adder.b;
  local_nested.local.sum_adder.sum.a = local_nested.local.sum_adder.a;
  local_nested.local.sum_adder.sum.b = local_nested.local.sum_adder.b;
  global.sum.b + (-local.sum_adder.sum.b) + (-local_nested.local.sum_adder.sum.b) + (-local_nested.sum_adder.sum.b) = 0.0;
  global.sum.a + (-local.sum_adder.sum.a) + (-local_nested.local.sum_adder.sum.a) + (-local_nested.sum_adder.sum.a) = 0.0;
end global_sum_test.test_model;
  }}}
}}}

which removes the 6 additional equations and makes the method work excellently. 

I am not sure what the specification of Modelica says here, but I guess it works because it cannot find the inner declaration of the Sum_port and therefore somehow does not generate the 6 equations which would break it.

'''New frontend Instantiating global_sum_test.test_model:'''

The new frontend does behave the same in the first case (except it reorders the generated equations).

{{{
#!div style=""font-size: 100%""
""outer"" keyword not present:
  {{{#!modelica
  class global_sum_test.test_model
  Real global.sum.a;
  Real global.sum.b;
  parameter Real local.a = 0.5;
  parameter Real local.b = 1.0;
  Real local.sum_adder.sum.a;
  Real local.sum_adder.sum.b;
  Real local.sum_adder.a = local.a;
  Real local.sum_adder.b = local.b;
  parameter Real local_nested.a = 0.5;
  parameter Real local_nested.b = 1.0;
  Real local_nested.sum_adder.sum.a;
  Real local_nested.sum_adder.sum.b;
  Real local_nested.sum_adder.a = local_nested.a;
  Real local_nested.sum_adder.b = local_nested.b;
  parameter Real local_nested.local.a = 0.5;
  parameter Real local_nested.local.b = 1.0;
  Real local_nested.local.sum_adder.sum.a;
  Real local_nested.local.sum_adder.sum.b;
  Real local_nested.local.sum_adder.a = local_nested.local.a;
  Real local_nested.local.sum_adder.b = local_nested.local.b;
equation
  global.sum.a + (-local_nested.local.sum_adder.sum.a) + (-local_nested.sum_adder.sum.a) + (-local.sum_adder.sum.a) = 0.0;
  global.sum.b + (-local_nested.local.sum_adder.sum.b) + (-local_nested.sum_adder.sum.b) + (-local.sum_adder.sum.b) = 0.0;
  local.sum_adder.sum.a = 0.0;
  local.sum_adder.sum.b = 0.0;
  local_nested.sum_adder.sum.a = 0.0;
  local_nested.sum_adder.sum.b = 0.0;
  local_nested.local.sum_adder.sum.a = 0.0;
  local_nested.local.sum_adder.sum.b = 0.0;
  local.sum_adder.sum.a = local.sum_adder.a;
  local.sum_adder.sum.b = local.sum_adder.b;
  local_nested.sum_adder.sum.a = local_nested.sum_adder.a;
  local_nested.sum_adder.sum.b = local_nested.sum_adder.b;
  local_nested.local.sum_adder.sum.a = local_nested.local.sum_adder.a;
  local_nested.local.sum_adder.sum.b = local_nested.local.sum_adder.b;
end global_sum_test.test_model;
  }}}
}}}

But when I want to use the same trick by adding the ""outer"" keyword the new frontend generates an inner declaration automatically so the trick does not work. During translation it warns:

[1] 21:56:43 Translation Warning
[global_sum_test: 15:5-15:23]: An inner declaration for outer component sum could not be found and was automatically generated.

{{{
#!div style=""font-size: 100%""
""outer"" keyword is present:
  {{{#!modelica
  class global_sum_test.test_model
  Real global.sum.a;
  Real global.sum.b;
  parameter Real local.a = 0.5;
  parameter Real local.b = 1.0;
  Real local.sum_adder.a = local.a;
  Real local.sum_adder.b = local.b;
  parameter Real local_nested.a = 0.5;
  parameter Real local_nested.b = 1.0;
  Real local_nested.sum_adder.a = local_nested.a;
  Real local_nested.sum_adder.b = local_nested.b;
  parameter Real local_nested.local.a = 0.5;
  parameter Real local_nested.local.b = 1.0;
  Real local_nested.local.sum_adder.a = local_nested.local.a;
  Real local_nested.local.sum_adder.b = local_nested.local.b;
  Real sum.a;
  Real sum.b;
equation
  global.sum.a + (-sum.a) = 0.0;
  global.sum.b + (-sum.b) = 0.0;
  sum.a = 0.0;
  sum.b = 0.0;
  sum.a = local.sum_adder.a;
  sum.b = local.sum_adder.b;
  sum.a = local_nested.sum_adder.a;
  sum.b = local_nested.sum_adder.b;
  sum.a = local_nested.local.sum_adder.a;
  sum.b = local_nested.local.sum_adder.b;
end global_sum_test.test_model;
  }}}
}}}

which obviously does not work.

I do like the possibility of using the method as it worked in the old frontend when the ""outer"" keyword was present. It is very very useful in cases where the model is relatively nested, so one does not have to code the sum manually which is tedious, but I think it actually works because of some bug (at least the translation error suggests that). What do you think about this? Should the new frontend also automatically generate the inner declarations. Or is there some other way to do these sums so seamlessly? I am confused...
"	discussion	closed	normal	1.14.1	Frontend	v1.14.1	invalid	inner outer flow connect