Tuesday, October 18, 2005

minimal controller for circle-diamond discrimination task

here's an update on these experiments...

changes:
1. binary genotype added on top of the real-valued genotype so as to turn on/off internode connections and also stateless/statefull nodes. 30 binary genes in total. 5 for the 5 time-constants of the 5 inter-nodes which are modified to same value as the time-step of integration in the case of 0 and to the mapped value on the real in the case of 1. 25 values for the inter-node connections between the 5 inter-nodes. 0 corresponds to no connection and 1 corresponds to a connection with the strength of the real-valued mapped gene.
2. sensory and motor nodes have no state (time-constant = time-step of integration).

sets of experiments:
[a] gradual fitness: smaller weights and smaller time-constants improve fitness.
[b] threshold fitness: fitness only improves if inter-connection weights are off and time-constants are off - smaller doesn't count.

results so far:
out of 5 runs 1 was fully successful. it evolved the first 1000 generations with fitness function from set [a] and the last 100 with the fitness function from set [b] given that it needed to prune out only one more recurrent connection which was already very low (i.e. 0.48). (will add some figures soon!)

plan:
plan to leave 20 runs for fitness function [b] and cross my fingers.
that should be it.
hopefully at least a couple of reactive solutions evolve in which case i shall analyse them and report them to our friends at indiana ;)

1 Comments:

At 9:49 pm, Blogger eduardo said...

update on the update:
100 experiments in total running.
5 sets. A: networks constrained to be purely reactive; B: networks constrained to be purely non-reactive; C: reactivity is evolvable with the binary genotype with selection pressure towards simpler (i.e. reactive) networks. C1: population starts off reactive; C2: population starts off purely non-reactive; C3: population starts off somewhere randomly in-between.

- have the steady state procedure ready to analyse how the behaviour is produced from the agent-environment interaction.

- want to implement the parameter to morph from circle to diamond to study the categorisation performance but are having some problems with it.

- reading the papers and writing the structure of a 'report'

 

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