Modelica In Action
This repository contains examples that demonstrate how to create, compile and simulate Modelica models using JModelica.org.
make commands mentioned in this guide reference the
located in the root directory of this repository.
In order to simplify your life the repository contains all the code necessary to create a Docker container that runs JModelica.org. In case you wonder what's a Docker container
Docker containers wrap a piece of software in a complete filesystem that contains everything needed to run: code, runtime, system tools, system libraries – anything that can be installed on a server. This guarantees that the software will always run the same, regardless of its environment (see https://www.docker.com/what-docker for more info).
In this case I created a "recipe", also known as Docker file, that describes how to build a container with installed everything that's needed to work with JModelica.org.
Once created and started, the container and your computer will interact as shown in the following image.
Upon start, some folders included in this repository will be shared with the container, in the meantime the container runs an IPython server. The container exposes the port used by the IPython server to your local machine. In this way you can connect to the IPython server in the container with a browser. Once you access the IPython server you can start working with JModelica.org.
The Docker container is based on a so called image (something similar to a snapshot of a virtual machine). To create the image you have two options
manually build the image with the command
download the image with the command
The second option is preferable because it doesn't require you to wait while Docker compiles from source JModelica.org and all its dependencies.
As of November 28 2018, there are two version of the image: 1.0 and 2.0, the latter has
installed a more recent version of JModelica as well as Jupyter notebook instead of IPython.
To download the version you're interested in, add the
VERSION=x.0 to the make rules
you invoke, for example to download the image version 2.0 run
make download-image VERSION=2.0
You can verify that the container image has been built (or downloaded) using the command
docker images. In my case when I run the command I see
$ docker images REPOSITORY TAG IMAGE ID CREATED SIZE modelicainaction/jmodelica 2.0 7f7f224e3da2 23 hours ago 3.1GB ubuntu 18.04 93fd78260bd1 9 days ago 86.2MB ubuntu 16.04 f753707788c5 23 months ago 127.2 MB modelicainaction/jmodelica 1.0 adcc4c39b0d6 23 months ago 2.7GB
Starting the container
Once the container image has been created we can start it.
To start the container run the command
make start. Again, you can choose which version
to run by specifying the version like
make start VERSION=2.0. This command starts
the container with installed JModelica.org and an IPython notebook server
listening on port 8888. The same port used by the IPython/Jupyter server is exposed
by the container and redirected to the localhost.
This means that if you open a browser and go to http://127.0.0.1:8888 you should see something
By default the container is configured to share the following folders
modelica- a folder containing the source code of the Modelica models used in the examples
ipynotebooks- a folder containing the ipython notebooks with examples
Every Modelica model located in the folder
modelica will be immediately visible
to JModelica.org. The same is true for the folder
ipynotebooks, every notebook it contains
will be automatically visible when you open the browser and go to http://127.0.0.1:8888.
You can verify that the container is running with the command
docker ps -a
$ docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 639bd33a27fb modelicainaction/jmodelica:1.0 "sh -c 'ipython noteb" 4 hours ago Up 4 hours 127.0.0.1:8888->8888/tcp prickly_mayer
and you can stop and remove the container (not the container image) with the command
docker stop 639bd33a27fb && docker rm 639bd33a27fb where
639bd33a27fb is the
- Version 2.0 uses Jupyter instead of IPython notebooks, and it requires to prompt a password when you connect
to the server from your browser. The password is
- I've seen some warnings and minor problems when running the examples in the most recent version 2.0. Unfortunately JModelica.org documentation doesn't seem to be up to date and I can't do much about it. I was still able to run simulations, but as usual use it at your own risk!