Some of the errors are not really errors (even if they are reported as such), the model works to simulate.

What problems did you had with nightly builds? I think they are far better than the stable releases.

Cheers,
Adrian Pop/

I think you would be better off with the nightly build since you need a patched version of MSL 3.2.1 in order to run the older stable releases. This mainly affects MultiBody.World, which previously has been patched in OpenModelica.

For DCPM/AIMC it generates errors but still works.

The Solenoid actuator is not an example. It is an example package (contains examples).

Hey, thanks so much for the response. I don't have record of errors as of now, but remember seeing many examples not running (in nightly build)...
But as both of you are suggesting the nightly build, I'll re-install with nightly build, and get back to you.

Hi!
  I've installed nightly build. I'm running the double pendulum example in mechanics. I"m getting this error -
  [:0:0-0:0] Error: Error occurred while flattening model Modelica.Mechanics.MultiBody.Examples.Elementary.DoublePendulum
  [/usr/lib/omlibrary/Modelica 3.2.1/Mechanics/MultiBody/Parts.mo:894:5-895:13] Error: Class world__gravityAcceleration not found in scope Modelica.Mechanics.MultiBody.Parts.Body (looking for a function or record).
  [:0:0-0:0] Notification: Instantiation of DoublePendulum failed.

  Similar Problem when running Mechanics -> Systems- RobotR3 -> Full Robot -
   [:0:0-0:0] Error: Error occurred while flattening model Modelica.Mechanics.MultiBody.Examples.Systems.RobotR3.fullRobot
   [/usr/lib/omlibrary/Modelica 3.2.1/Mechanics/MultiBody/Parts.mo:894:5-895:13] Error: Class world__gravityAcceleration not found in scope Modelica.Mechanics.MultiBody.Parts.Body (looking for a function or record).
   [:0:0-0:0] Notification: Instantiation of fullRobot failed.

   Good thing is some errors are not being generated.  For example, when I last time ran examples in Fluid systems, there were some errors in nightly build. I'm not seeing them in fresh installation of nightly build. But I have this problem repeatedly appear in mechanical problems -  Error: Class world__gravityAcceleration  not found

How do I resolve this??


 

What is the output of:

$ dpkg -l omc omlib-modelica-3.2.1 omlib-complex-3.2.1 omlib-modelicaservices-3.2.1

  I'm seeing the old problems I used to see in the nightly build. I think that happened because I did software update in available in Debian, which I think installed newer versionf of openmodelica codes. I'll first show the errors that are being generated -
When try to simulate double pendulum - mechanics multibody example
[:0:0-0:0] Error: Internal error Transformation Module PFPlusExt index Reduction Method Pantelides failed!
[:0:0-0:0] Error: Internal error - IndexReduction.pantelidesIndexReduction failed!
[:0:0-0:0] Error: Internal error IndexReduction.pantelidesIndexReduction failed! Found empty set of continues equations. Use +d=bltdump to get more information.

When I try to simulate Fluid -> Examples -> Pumping System -
[:0:0-0:0] Error: Error occurred while flattening model Modelica.Fluid.Examples.PumpingSystem
[/usr/lib/omlibrary/Modelica 3.2.1/Fluid/Examples/PumpingSystem.mo:52:5-54:75] Error: Failed to elaborate expression: {Modelica.Fluid.Vessels.BaseClasses.VesselPortsData(diameter = 0.3), Modelica.Fluid.Vessels.BaseClasses.VesselPortsData(diameter = 0.3), Modelica.Fluid.Vessels.BaseClasses.VesselPortsData(diameter = 0.01)}.

When I tried to do heat exchange simulation in fluids -
43 warnings and 4 errors generated.
make: *** [Modelica.Fluid.Examples.HeatExchanger.HeatExchangerSimulation.o] Error 1
Compilation process exited with code 2

And this is what I got when I ran dpkg command ->

dpkg -l omc omlib-modelica-3.2.1 omlib-complex-3.2.1 omlib-modelicaservices-3.2.1
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                            Version              Architecture         Description
+++-===============================-====================-====================-====================================================================
ii  omc                             22602-1              i386                 The OpenModelica Compiler
ii  omlib-complex-3.2.1             6931-om1-1           all                  Complex 3.2.1 is a Modelica library
ii  omlib-modelica-3.2.1            7867-om1-1           all                  Modelica 3.2.1 is a Modelica library
ii  omlib-modelicaservices-3.2.1    6931-om1-1           all                  ModelicaServices 3.2.1 is a Modelica library



Thank you for your time and support!

Can you run the following in a mos-script? (Put in file a.mos, in some working directory you can easily clean)

loadModel(Modelica);getErrorString();

buildModel(Modelica.Mechanics.MultiBody.Examples.Elementary.DoublePendulum);getErrorString();

Then run command omc a.mos.

You could also do the same with OMShell and see if it works. If it does, it is OMEdit that is broken (it does not seem to work for me either; must be a regression).

Ha ha. I've not used omc at terminal before....
But I just did what you asked. (created a folder called "mod".
This is the output I got at terminal...
vi a.mos
omc a.mos
true
""
{"/home/xxxxxxxxx/mod/Modelica.Mechanics.MultiBody.Examples.Elementary.DoublePendulum","Modelica.Mechanics.MultiBody.Examples.Elementary.DoublePendulum_init.xml"}
""
And I've got so many files created. So how do I check if the results are okay?

Hi,

This is a bug that needs to be fixed. Somehow simulation works fine in command line but it fails in OMEdit.
I added a ticket for it and I started looking into it:
https://trac.openmodelica.org/OpenModelica/ticket/2871

Cheers,
Adrian Pop/

Hi again,

I now fixed the bug and if you get the nightly builds tomorrow, they should work fine.

Cheers,
Adrian Pop/

Thank you!!! Apologize I could not reply earlier.

I ran updates and I could run pendulum problem smoothly.
For Heat exchanger simulation I saw some message like this -->
/tmp/OpenModelica_xxxxxxxxxxx/OMEdit/Modelica.Fluid.Examples.HeatExchanger.HeatExchangerSimulation -port=35128 -logFormat=xml -w -lv=LOG_STATS
Simulation process exited with code 255

And for  Fluid -> Examples -> Pumping System -
/tmp/OpenModelica_xxxxxxx/OMEdit/Modelica.Fluid.Examples.PumpingSystem -port=55007 -logFormat=xml -w -lv=LOG_STATS
stdout        | warning     | While solving non-linear system an assertion failed during initialization.
|        | |     | | The non-linear solver tries to solve the problem that could take some time.
|        | |     | | It could help to provide better start-values for the iteration variables.
|        | |     | | For more information simulate with -lv LOG_NLS
LOG_NLS        | warning     | nonlinear system 92 fails: at t=0 Debug more
|        | |     | | proper start-values for some of the following iteration variables might help
|        | |     | | [1] Real reservoir.s[1](start=3, nominal=1)
|        | |     | | [2] Real pipe.flowModel.states[2].p(start=100000, nominal=100000)
assert        | debug     | Solving non-linear system failed at time=0.
For more information please use -lv LOG_NLS. Debug more
assert        | info     | simulation terminated by an assertion at initialization
Simulation process exited with code 255

Both are exiting with code 255... Is this something I've to worry about?

Thank you!

Hi,

Unfortunately not all the models can currently be simulated.
There are still some issues in the back-end and the runtime system but we're working on fixing them.
You can always see the current status of the library coverage (what compiles and what simulates ) here:
https://test.openmodelica.org/libraries/trend.html
so you know what to expect.

You can click on any image to get to an overview of the library coverage run.

Cheers,
Adrian Pop/

Thank your for reply.. And it's good that you told me about status of library coverage.
I think openmodelica is a really great tool, and I feel that I should also contribute in any way I can.
I'm just learning OpenModelica, and I've some experience in programming. If there is some work I can take up, I'll be happy to do so.
Can you let me know what are the ways I can contribute? [Coding/Writing Tutorials/ etc].  One thing I'm already doing is writing tutorials for an absolute beginner (say, for engineering students, and conducting workshops on it..)
Another thing I'm thinking is writing libraries..

Best Wishes

I've been thinking about this a bit. Documentation in OpenModelica is lacking a bit (some old, unsupported things are documented, and new things are not).

But one thing that really would help is to update old libraries. Every now and then someone will try to use an old Modelica 1.x or 2.x library with OpenModelica and it will just fail. Because so many things are just wrong in the old libraries. This is a lot of work in some cases (there are "Modelica" libraries out there that should not even pass a Modelica lexer).

Do you know that there exist an official modelica tutorial by the modelica association?
It is in theory very well done, but VERY old: it refers to Modelica 1.4 and was written in December 2000
There is a ticket open on the Modelica association site about volunteers wanting to update that tutorial:
    https://trac.modelica.org/Modelica/ticket/106
Maybe you are the right volunteer?

MC

There is a more recent (short) Modelica tutorial here: http://tour.xogeny.com

sjoelund.se,
Sorry, for delayed response. i would definitely be interested in doing that. But I will need some guidance. I learn on my own, but small help here and there would be really great. So what I should do next?

ceraolo
Sounds really interesting work. I'll look into it.

sjoelund.se
The link you provided isn't working.. at least for me. Even if it's working, as you said, it's short one. So do you think it would be appropriate if I write an detailed tutorial?

For fixing old libraries, most of them are hosted on https://github.com/modelica-3rdParty so fixing them is as easy as making a pull request in some cases. I know a lot of people who say some library is working in OpenModelica, but will not even go through the parser (loadFile). So a lot of libraries you don't even need to know the domain in order to fix...

As for larger tutorials, http://book.xogeny.com/ is not really a tutorial, but it does teach you most things you should know about Modelica

The link you provided isn't working.. at least for me. Even if it's working, as you said, it's short one. So do you think it would be appropriate if I write an detailed tutorial?

I had no problems in connecting to tour.xogeny.com
I liked the xogeny tutorial, that is much more than a pdf, contains chapters and  lessons in a structure way, examples and exercises.

However, answering to the Modelica.org ticket that I mentioned in my previous message would have the additional benefit of working on a tn "official" tutorial, i.e.  one that has been discussed and validated by the association.

Consider, for instance, that Dymola still includes in its distribution that old tutorial.