myPhysicsLab provides JavaScript classes to build real-time interactive animated physics simulations.

The myPhysicsLab website shows the simulations running and contains explanations of the math behind them.

myPhysicsLab is provided as open source software under the Apache 2.0 License. See the accompanying file named LICENSE. The author is Erik Neumann erikn@myphysicslab.com.

Source code is available at https://github.com/myphysicslab/myphysicslab.

It is possible to customize a myPhysicsLab simulation without building from source code, see Customizing myPhysicsLab Simulations.

To build from source code:

1. Download the myPhysicsLab source code from https://github.com/myphysicslab/myphysicslab. You can download a zip file from that github page, or use

    git clone https://github.com/myphysicslab/myphysicslab.git
   

2. Install the required tools:

   • TypeScript You should be able to execute tsc --version within the myphysicslab directory. Making an alias in your .bash_profile like this might be helpful:

       alias tsc=~/Documents/Programming/myphysicslab/node_modules/typescript/bin/tsc
     

   • esbuild Make a symbolic link to the esbuild executable within the myphysicslab directory.

       ln -s node_modules/esbuild/bin/esbuild esbuild
     

     You should then be able to execute ./esbuild --version within the myphysicslab directory

   • Perl

   • GNU Make

3. Execute tsc at the command line. This will compile all the typescript .ts files to become JavaScript .js files in the build directory.

4. Execute make at the command line. This creates .html files and bundled .js files in the build directory for all applications and tests in all language versions. Execute make help to see available options.

5. Open the file /build/index-en.html with a browser. This has links to all the example files that were built.

See Building myPhysicsLab Software for more information about the build process.

Here are some hints about installing tools, this was on MacOS. Following this page I used HomeBrew to install node, and then used node's npm to install the other tools locally inside the myphysicslab directory:

    cd myphysicslab
    npm install typescript
    npm install esbuild

Those commands create some directories and files (for example node_modules) inside the myphysicslab directory that are unrelated to the myphysicslab project. The .gitignore file contains entries to prevent these from being added to the myphysicslab project.

Test whether your installation is ready to build myphysicslab:

    cd myphysicslab
    tsc --version
    ./esbuild --version
    perl --version
    make --version

See myPhysicsLab Documentation for overview of architecture and for detailed documentation of software.

Building the documentation requires some additional tools, see Building myPhysicsLab Software

There are around 50 different simulations in the source code, each of which has has an example file which is mainly for development and testing. Find them in the examples index.

myPhysicsLab was started in 2001 using Java. From 2013 to 2016 the code was converted to JavaScript that depended on Google Closure Compiler.

In 2023 the code was converted to TypeScript for a couple of reasons: to be able to generate documentation, and because Google Closure Library is being retired.

Because of how modules work in TypeScript, sometimes several classes or interfaces are combined into a single file. For example the file util/Observe.ts contains what was previously in 10 separate files. This can make finding things a little harder in the new scheme.