Displaying parameter in annotation in DYMOLA

问题

I have a simulation model using different components. In order to get a quick overview of the used parameters I use the functionality of annotations to display certain model parameters (e.g. m_flow_nominal) via:

textString="Nominal Flow Rate = %m_flow_nominal"

in the annotation dialog. Which will give out something like

Nominal Flow Rate = 5

This is working perfectly fine for parameters that are integers.

I also have a parameter that is calculated from other values. Like, let's say the Volume of a body. When I try to display this parameters via:

textString="Volume = %volume"

Instead of the final value I will be given the formula the volume is calculated with. For example

Volume = a * b * c

How can I display the final value of the volume in this case, instead of the formula?

Here is the actual problem:

  parameter Modelica.SIunits.Length xBorFie = 10 "Borefield length";
  parameter Modelica.SIunits.Length yBorFie = 30 "Borefield width";
  parameter Modelica.SIunits.Length dBorHol = 5 "Distance between two boreholes";

  parameter Integer nXBorHol = integer((xBorFie+dBorHol)/dBorHol) "Number of boreholes in x-direction";
  parameter Integer nYBorHol = integer((yBorFie+dBorHol)/dBorHol) "Number of boreholes in y-direction";
  final parameter Integer nBorHol = nXBorHol*nYBorHol "Number of boreholes";

When using

textString="Number of boreholes = %nBorHol"

I get

Number of boreholes = nXBorHol*nYBorHol

回答1:

I think the only possibility is to use the DynamicSelect() function. This can be used to show a changing value within e.g. an icon. To use it you will have to manually adapt the Icon annotation. It is documented in the Modelica Language Specification 3.4, Section 18.6.6.

Some good examples of how this DynamicSelect() can be used are:

Modelica.Blocks.Interaction.Show.RealValue shows how to display a value
Modelica.Blocks.Interfaces.partialBooleanSO shows how to change line- and fill colors of icons
Modelica.StateGraph.Examples.Utilities.Tank shows how to change the size of a rectangle to display the level within a tank

The disadvantage of DynamicSelect() is that it will sometimes need to initialize/simulate the model before showing a value (I think if it is not computed from literals or parameters). The advantage is that they are updated during the simulation when looking at the model.

For your case the implementation of the icon could look like:

    annotation (Icon(graphics={Text(
      extent={{-100,-20},{100,20}},
      lineColor={0,0,0},
      textString="NoB=" + DynamicSelect("?", String(nBorHol)))}));

which results in the icon showing

NoB=21

For me it also immediately adapts when changing one of the respective parameters.

来源：https://stackoverflow.com/questions/52608262/displaying-parameter-in-annotation-in-dymola

标签

parameters

annotations

dymola