OpenModelica FAQ

Version 2007-09-03.

Below are some frequently asked questions in three areas, with associated answers.

If you can't find your answer here please also check the searchable archive of our OpenModelicaInterest@ida.liu.se
mailing list in which we answer OpenModelica related questions.

OpenModelica General

Q: Why are not the MultiBody and Media libraries included in the OpenModelica distribution.
A: These libraries need special features in the Modelica language which are not yet implemented in OpenModelica. We are working on it, but it will take some time.

Q: I did not find the graphic editor MathModelica Lite in the OpenModelica distribution. Where can I find it?
A: You can download it via a link at the OpenModelica web site, e.g. the one placed under the OpenModelica Environment heading, Graphic Editor bullet.
     Also available at MathModelica Lite page hosted at Mathcore Engineering AB

Q: OpenModelica 1.4.3 does not read the MODELICAPATH environment variable, even though this is part of the Modelica Language Specification.
A: Use the OPENMODELICALIBRARY environment variable instead. We have temporarily switched to this variable, in order not to interfere with other
    Modelica tools which might be installed on the same system. In the future, we might switch to a solution with a settings file, that also allows the user to turn
    on the MODELICAPATH functionality if desired.

Q: How do I enter multi-line models into OMShell since it evaluates when typing the Enter/Return key?
A: There are basically three methods:
     1) load the model from a file using the pull-down menu or the loadModel command.
     2) Enter the model/function as one (possibly long) line.
     3) Type in the model in another editor, where using multiple lines is no problem, and copy/paste the model into
         OMShell as one operation, then push Enter. Another option is to use OMNotebook instead to enter and evaluate models.

Q: There is a problem at installation of OpenModelica 1.4.3 on Windowx XP – MicroSoft .NET Framework 1.1. missing
A: Try the latest nightly build of OpenModelica.

OMNotebook

Q: OMNotebook hangs, what to do?
A: It is probably waiting for the omc.exe (compiler) process. (Under windows): 
    Kill the processes omc.exe, g++.exe (C-compiler), as.exe (assembler), if present.
    If OMNotebook then asks whether to restart OMC, answer yes.
    If not, kill the process OMNotebook.exe and restart manually.

Q: After a previous session, when starting OMNotebook again, I get a strange message.
A: You probably quit the previous OpenModelica session in the wrong way, which left the process omc.exe running.
     Kill that process, and try starting OMNotebook again.

Q: I copy and paste a graphic figure from Word or some other application into OMNotebook, but the graphic does not appear. What is wrong?
A: OMNotebook supports the graphic picture formats supported by Qt 4, including the .png, .bmp (bitmap) formats, but not for example the gif format. 
    Try to convert your picture into one of the supported formats, (e.g. in Word, first do paste as bitmap format), and then copy the converted version into
    a text cell in OMNotebook.

Q: Plotting does not work in OMNotebook.
A: You probably have an old version of Java installed. Update your installation, and try again. 
    (Another known problem, soon to be fixed, is that plotting of parameters and constants does not yet work).

Q: I select a cell, copy it (e.g. Ctrl-C), and try to paste it at another place in the notebook. However, this does not work. 
     Instead some other text that I earlier put on the clipboard is pasted into the nearest text cell.
A: The problem is wrong choice of cursor mode, which can be text insertion or cell insertion. If you click inside a cell, the cursor become vertical, and
    OMNotebook expects you to paste text inside the cell. To paste a cell, you must be in cell insertion mode, i.e., click between two cells (or after a cell),
    you will get a vertical line. Place the cursor carefully on that vertical line until you see a small horizontal cursor. Then you should past the cell.

Q: I am trying to click in cells to place the vertical character cursor, but it does not seem to react.
A: This seems to be a Qt feature. You have probably made a selection (e.g. for copying) in the output section of an evaluation cell.
    This seems to block cursor position. Click again in the output section to disable the selection. After that it will work normally.

Q: I have copied a text cell and start writing at the beginning of the cell. Strangely enough, the font becomes much smaller than it should be.
A: This seems to be a Qt feature. Keep some of the old text and start writing the new stuff inside the text, i.e., at least one character position to the right.
    Afterwards, delete the old text at the beginning of the cell.

OMDev - OpenModelica Development Environment

Q: I get problems compiling and linking some files when using OMDev with the MINGW (Gnu) C compiler under Windows.
A: You probably have some Logitech software installed. There is a known bug/incompatibility in Logitech products. 
    For example, if LVprcsrv.exe (LV*.exe) is running, kill it and/or prevent it to start again at reboot;
    it does not do anything really useful, not needed for operation of web cameras or mice.