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From Ref:ullman2014learning:

Humans acquire their most basic physical concepts early in development, but continue to enrich and expand their intuitive physics throughout life as they are exposed to more and varied dynamical environments. We introduce a hierarchical Bayesian framework to explain how people can learn physical theories across multiple timescales and levels of abstraction.

The implementation of this computational model requires Ikarus scheme. Follow these instructions to install Ikarus and run the model:

  1. Log into a compatible computer. We recommend launching a 32-bit Ubuntu version such as ubuntu-trusty-14.04-i386-server-20140724 on EC2. To find this machine image, search for ami-07b4b742 under Community AMIs. After launch, log in:

     ssh -i my-keypair.pem ubuntu@ec2-...compute.amazonaws.com
  2. Install required packages:

     sudo apt-get update
     sudo apt-get install build-essential autoconf m4 automake perl
     sudo apt-get install libgsl0-dev libffi-dev libgmp3-dev
     sudo apt-get install git unzip bzr
  3. Install Ikarus Scheme:

     wget http://stuhlmueller.org/data/ikarus.zip
     unzip ikarus.zip
     cd ikarus.dev-derick
     ./configure --enable-libffi
     sudo make install
     cd ..
  4. Install scheme-tools:

     git clone https://github.com/stuhlmueller/scheme-tools.git
     export IKARUS_LIBRARY_PATH=~/scheme-tools/:$IKARUS_LIBRARY_PATH
  5. Download the “Learning Physics” Scheme code:

     wget http://stuhlmueller.org/data/ullman-physics2015.zip
     unzip ullman-physics2015.zip
     export IKARUS_LIBRARY_PATH=~/ullman-physics2015/:$IKARUS_LIBRARY_PATH
  6. Run the Scheme code (in this example: world 1, scenario 2):

     cd ullman-physics2015
     mkdir inference
     mkdir inference/world1/
     ikarus --script run-inference.ss 1 2

The inference results are written to inference/world1/world1_1.

A note on runtime: A forward-step of simulating physics is on the order of a second. However, depending on your setup and the number of theories being inferred, the inference step may take several hours.