CTRNN is a MAX external that implements a Continuous-Time Recurrent Neural Network, a dynamical systems model of a biological neural network. When combined with evolutionary algorithms, CTRNNs can perform simple cognitive tasks.
A CTRNN uses a system of ordinary differential equations (ODE) to model the effects on a neuron receiving an input spike train. For example, a simulated "creature" can learn the best way to walk in a process that is as follows:
- Create a population of CTRNNs with random internal state values to control a creature's locomotion
- Observe which individual CTRNN has the creature crawling the furthest (via an objective function)
- Use the best individuals from the population to create new CTRNNs
- Repeat for a few thousand generations.
Afterwards, you'll have a CTRNN that's very skilled at controlling creature locomotion. Though the initial population may have produced hobbling, the final generations will coordinate smooth locomotive behaviour. In the literature, CTRNNs have been "evolved" thusly to control various tasks from chemotaxis to simple learning.
This work provides a simple, efficient implementation to be used in MAX, where the neural network I/O can be embedded as to a host of multimedia applications.
To build, open up a Terminal window and run javac with the -classpath set to the location of your MAX5 or MAX6 installation. The full command is as follows. This will produce a number of .class files that Max6 will load whenever you open up a patch with this external. You have to ensure your search paths are setup correctly in MAX, so that it can find these .class files.
javac CTRNN.java MersenneTwisterFast.java CTRNNSettings.java CTRNNWrapper.java -classpath /Applications/Max6/Cycling\ \'74/java/lib/max.jar
You need to be comfortable patching in MAX. There's a bit of a learning curve, but the creative yield will be great!
This code has been run on MacOS 10.5-10.7, with both Max5 and Max6.
This work is largely influenced by:
- The biologically inspired Dynamical Systems research of Dr. Randall Beer
- The Live Algorithms research and MAX patches by Dr. Ollie Bown
CTRNN is Copyright © 2010-2011 iroro orife
Java source code and MAX patch are provided under the MIT License
Initial commit