I will try to cover this is today's session.

Hello Carl,
I'll try to help on this, if it continues not to work, please inform so Ankit can help further.

Starting from a fresh Kernel, ie Evalutation>Quit Kernel>StartKernel.
It works for me (WM 14, SM14) when I run this sequence of commands,

Text Line : Load the system modeling functionalities:

SystemModel;

Text LIne : Load the model diagram:

modelName = "ModelingPrinciples.Coffee.Exercises.Step1";

Now when you type the command below, on starting to type the Quotation mark, you will initially only see the leading Quote and the drop down menu of options to choose from. Once "Diagram" is selected the command is populated with "Diagram"

SystemModel[modelName, "]

Hope this was helpful,
John Burgers.

(Question) In Step 6 - Calibrate Parameters of Analyzing Models with Wolfram Language (the 2nd lecture),

• Plot the experimental data: -> what are the measured data (= calibrated parameters)? data = {{0, 80}, {900, 45}, {1800, 25}} -> the name of the parameters? e.g., thermometer temperature? ambient temperature? i.e., 0 is the value of ? -> Likewise, 900 and 1800 are the values of ? (which parameter) 80 is the value of ? -> Likewise, 45 and 25 are the values of ? (which parameter)

-> as always, Vedat Senol asked that for us during the lecture. However, I still have the same question.

*** Vedat Senol always asked questions that I had, which I appreciate. I can't ask the questions during the lecture because I should focus on the lecture. While typing my question, I will get lost. BigMarker does not allow us to ask our questions verbally. Thus, Vedat Senol's questions are very important for me to study well. Could Vedat Senol come back to the Daily Study Group? Vedat Senol, could you please make time for us?

In regard of the mass of CO2 in the atmosphere in the year 2002:

rs1 = Solve[
   Eliminate[{xCO2 == nCO2/nAir, mAir == nAir*MAir, 
     mCO2 == nCO2*MCO2}, {nCO2, nAir}], mCO2][[1]]

gives

{mCO2 -> (mAir MCO2 xCO2)/MAir}

With data from Wolfram Alpha and Mathematica:

UnitConvert[
mCO2 //. 
Join[rs1, {mAir -> 
WolframAlpha[
"mass of atmosphere", {{"Result", 1}, "ComputableData"}], 
MCO2 -> ChemicalData["CO2", "MolarMass"], 
MAir -> ChemicalData["Air", "MolarMass"], 
xCO2 -> UnitConvert[
WolframAlpha[
"global carbon dioxide concentration 2002", {{"Result", 4}, 
"ComputableData"}][[2, 3]]]}], "MetricGigatons"]

gives

Quantity[2915.77, "MetricGigatons"]

Dear Ankit Naik

Great presentation today! I kind request. If there is the opportunity, please talk about taking advantage of the large amounts of models that have been developed in Modelica language that can be imported from Wolfram SystemModeler.

Best regards

Jesus

Sure, I will. I plan to talk about it in Friday's session.

For people following this post and new to Modelica, you can learn about the Modelica language here: https://www.wolfram.com/system-modeler/resources/what-is-modelica/

I would like to ask a question, it is not clear to me in any system or subsytems, how many variables are "inputs" and how many "outputs" and where is this defined. I understand in a simulation all variables are then calculated for the entre time span

Hi Carl,

Not from System Modeler, but you can create such diagrams (Sankey diagram) using the Wolfram Language.

Once you are done with the simulation, you can extract the results from your simulation in Wolfram Language. Then use the results to create such diagrams. Here are some implementations that might be useful:

https://mathematica.stackexchange.com/questions/166439/how-to-make-a-sankey-diagram https://resources.wolframcloud.com/FunctionRepository/resources/AlluvialChart/

The easiest way of recognising inputs and outputs, for example, in a give component, is by looking at the connectors that are available in the icon of the component. Depending on the physical quantity, the connectors have different graphical representations. These are usually triangles of different colours.

In a broader sense, if you write your models, you can make any variable and input, output or none. When you make a variable input or output, there are some restrictions applied to it. For example, you will get an error when trying to connect outputs to outputs. It’s like an extra level of safety when creating your model.

All the variables are calculated when simulation is running, and the inputs will be calculated based on the output that you have connected to it. There is a special case, a top-level input, which is an input in the highest hierarchy of your model. In that case, if left unconnected, it will take a default value of zero.

Hi John,

Thank you!

1. I am not able to follow the question. To view the icon of a model or a component, you can open the model by double-clicking on it then press Ctrl + 1 to view the Icon and Ctrl + 2 to get back to the diagram view. You can refer to Step 1 in the Solution folder to check if your Step 1 in the Exercises folder matches it.

2. I will probably cover the new file creation and the .sme file on Thursday next week. No, there is no requirement to save the .sme file with the model files.

Catching up with following along using my own System Modeler evaluation version.

When I first stored the plot, the text with the name of the new plot came out black in the top right hand corner, but when you did it it came out blue; and putting the cursor on the title no longer gave me any options to make changes to it, as it did when you did it live.

What is going on there?

I installed System Modeler version 14 and then Mathematica version 14. After that, I started System Modeler and opened ModelingPrinciples. Then,

Unresolved dependency in ModelingPrinciples ModelingPrinciples has a declared dependency on BusinessSimulation version 2.2.0-wsm. No version of BusinessSimulation is currently loaded.

Would you tell me why it occurred and how to fix it? The day before, I installed System modeler only and started the System Modeler to open ModelingPrinciples. Then, the same error occurred. I though that it might be because I did not instsall Mathamatica. However, now I know that it was not the reason for it.

I opened the ModelingPrinciples. Then, only grided blank with Model 1 shows. The same error occurred - i.e., no difference of Mathematica installation.

If anyone knows about why it occurred and how to fix it, would you help me on it?

I posted the question during the class yesterday, but did not get the answer.

Am I the only one who has the strange error?

I already found it soon after I posted the question :) Now I have the Businss Simulation Library installed in System Modeler. However, I can't change the name of Model. Your Model name is "ModelingPrinciples.Coffee.Exercises.Step1." My Model was named as "Model 1" when I opened "ModelingPrinciples." I have not been able to find how to change the Model's name. I even removed System Modeler, Mathematica, and models that I created to follow your lectures and started from the first beginning to downlod them. However, I still have the same issue. Why am I the only one who raises the issue? Am I the only one who has it? Or, am I the only one who asks about it?

I found "Modeling and Identification of Dynamic Systems" c2021 by Ljung et all available at adlibiris.com and biblio.com, though adlibirs only seems to ship to Sweden.

Hello Ankit,

I had troubles during the steps in WM 14 in the Start simple session. The solutions.step5 model crashed. Was this a common experience? Edit - I went back to this and found the problem, no need to answer.

I have a question also. Can you show how to save parameter adjustments made in Simulate back to the model?

Thank you, John

Thank you Ankit,

To further clarify, you were showing us that the documentation centre automatically create an icon version of the model in the documentation head. That didn't happen for me as I was following along with you.

John

Also the options like Frame->None are not recognized... The word "Frame" comes out in red font. Also if I use "false" same result...

OK so I answered my second question: The suggestion bar at the bottom of the graph is not creating a list of options. If I place the curly bracket like you did manually, it will accept the Frame->False or None options. I don't know if that's a bug with WL 14 or SM 14, but it's not working the way it should. I'm running both on a MAC.

Hi Soomi,

We will cover SystemModelCalibrate in tomorrow's session.

@Vedat Senol was sick last week. If he feels better then he should join from tomorrow.

Hi John,

In Simulation Center, go to File -> Save Experiment Settings -> Ok

Thanks! And I will definitely be looking at that circuits course.

Hi James,

Thanks for reporting, I have asked our team to look into it.

Hi Soomi,

I have asked the Wolfram U team to look into it. Hopefully, they can send the recording in a few hours (when the US office opens).

After the study group's end, for how long would we still be able to re-watch the videos?

The recordings will be hosted in Wolfram U as on-demand videos after the study group is over.

You can use the following to represent infinity: Modelica.Constants.inf

Type it in the parameters field. You can also find all the other type of constants in the package: Modelica.Constants

While reviewing the "Different Models" session I would like to try the creation and simulation of the model based upon the business library. By chance do you have a list of parameters for those components? Thank you, John

... continuing on these are the parameters I chose to when investigating the model behaviour, by simulating and then plotting the energy stored in the material stock components and on a second plot the power passing through the proportionalTransition components. It almost makes sense. My engineering sense is that the proportionalTransition components daisy chain the inertia so the electrical output appears to ramp up after the gear box comes up to speed, where as in reality the gearbox and generator come to speed at the same rate. Given that most energy would be generated at controlled rotor speed the small proportion of energy generation during speed transition is insignificant for this business model.

see the attached file for the Component Names, BaseType, OutputType and Parameters. The component models types can be seen on the class video recording.

Attachments:

DifferentModelsW...txt

Not sure. That file was not used in the sessions. I will ask the our team to remove it.

Hey Ankit, Did I miss this? How do you save things in a Session in System Modeler / Simulation Center so that you can close them and reopen and pick up where you left off? Is there a way to do that? Carl Also, where can you go to get easy to use Modelica models for electronic components and subsystems like microwave components that can be loaded into System Modeler? Like Couplers, mixers, amplifiers etc? Do they even exist?

Hi Carl,

Sorry for the late reply. This post is currently inactive. You can create a new post in the System Modeler group for future queries.

1. I don't think you can save a session. For Simulation Center: If you are analyzing a plot by creating measurements or updating plot legends then you can save the plot as a Model Plot. This will save the updates in the model and you can resume later. You can also try to export the results as a Simulation Executable (I covered this on Thursday 18th April) and reload the simulation results later.
2. Unfortunately, I am not aware of a library that has microwave components. The only relevant library that comes to mind is Modelica.Electrical.Analog.