Problem with switching units of vector parameters using the GUI of OMEdit

[christiankral]

Description

Polyphase models rely on parameter vectors. Consider the following Modelica model:

model Test
  Modelica.Electrical.QuasiStatic.Polyphase.Basic.Resistor resistor(R_ref = {100, 100, 100})  annotation(
    Placement(visible = true, transformation(origin = {40, 50}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  Modelica.Electrical.QuasiStatic.Polyphase.Basic.Star star annotation(
    Placement(visible = true, transformation(origin = {10, 50}, extent = {{10, -10}, {-10, 10}}, rotation = 0)));
  Modelica.Electrical.QuasiStatic.SinglePhase.Basic.Ground ground annotation(
    Placement(visible = true, transformation(origin = {-10, 10}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
equation
  connect(ground.pin, star.pin_n) annotation(
    Line(points = {{-10, 20}, {-10, 50}, {0, 50}}, color = {85, 170, 255}, pattern = LinePattern.Solid));
  connect(star.plug_p, resistor.plug_p) annotation(
    Line(points = {{20, 50}, {30, 50}}, color = {85, 170, 255}, pattern = LinePattern.Solid));

annotation(
    uses(Modelica(version = "4.0.0")));
end Test;

So, for example, the parametes of the quasi stsatic reistor model are R_ref = {100,100,100}

If I change the unit of the resistances to kOhm

the GUI applies R_ref (displayUnit = "kOhm")= {100, 100, 100} which causes an error when I try to simulate the model, as each is missing for the displayUnit.

Even switching back to the original unit Ohm does note resolve the issue.

Steps to Reproduce

• Create the model above
• Simulate the model (everything is OK)
• Make a double click on the resistor model and change the unit to to kOhm
• Press OK an simulate the model: it fails
• Switch to Text View an manually add the keyword each to resistor(R_ref (displayUnit = "kOhm")= {100, 100, 100}), resulting in: resistor(R_ref (each displayUnit = "kOhm")= {100, 100, 100})
• Simulate the model and it works OK

Expected Behavior

The each shall be included by the GUI automatically when switching to a different unit

Version and OS

Connected to OpenModelica 1.21.0~dev-256-g56379c0
Connected to OMSimulator unknown-linux

So this issue applies to the acutal nightly build version and back to version 19.2 (on Windows)

[christiankral]

@casella I consider this to be an issue that needs a fix in the next stable version. A user who can not guess what the problem is, will fail working with OpenModelica and possibly discontinue working with it, as it requires sophisticated Modelica knowledge to resolve the issue, even if the translation process drops a clear hint:

[Non-array modification ‘"kOhm"‘ for array component ‘displayUnit‘, possibly due to missing ‘each‘.]
(omeditmessagesbrowser:///Modelica.Electrical.QuasiStatic.Polyphase.Basic.Resistor?lineNumber=4)

[adeas31]

See also #5405, #5737, #7750

[adeas31]

@perost we need to extend the setElementModifierValue.
This is what we have right now setElementModifierValue(name, modifierName, expression) and we should update like this setElementModifierValue(name, modifierName, expression, final, each) where final and each are optional Boolean.

[perost]

@perost we need to extend the setElementModifierValue. This is what we have right now setElementModifierValue(name, modifierName, expression) and we should update like this setElementModifierValue(name, modifierName, expression, final, each) where final and each are optional Boolean.

You can already set final and each with the current API, for example: setElementModifierValue(M, R_ref, $Code((each displayName = "kOhm")={100, 100, 100})). Or do you need something else?

[adeas31]

As I remember it works for the submodifier but not for the actual modifier e.g., how to set each for R_ref?

[perost]

As I remember it works for the submodifier but not for the actual modifier e.g., how to set each for R_ref?

In the example model we have R_ref as a component in resistor, so you would do:

setElementModifierValue(Test, resistor, $Code((each R_ref = 1)))

As you say it only works for submodifiers, but setting each on something that isn't a submodifier doesn't make any sense. I.e. you can't have something like Real R_ref[:] = each 1.