Opened 2 months ago

Last modified 2 months ago

#3067 accepted enhancement

Crossover probability for SubtreeCrossover

Reported by: gkronber Owned by: gkronber
Priority: medium Milestone: HeuristicLab 3.3.17
Component: Encodings.SymbolicExpressionTreeEncoding Version: trunk
Keywords: Cc:

Description

Some genetic programming variants allow a copy operation where neither crossover nor mutation are applied to selected parent trees.

This is helpful for certain problem instances using a multi-tree representation (via MultiEncoding) where we want to prevent that a crossover event causes crossover for all trees.

One way to add this is to add a crossover rate to the general genetic algorithm variations that we are using in HL for GP.

Another and easier way is to implement this in the crossover operator using a crossover probability.

Change History (4)

comment:1 Changed 2 months ago by gkronber

r17490: add crossover probability for subtree crossover and initialized it to 100%

This change breaks reproduceability of old experiments because we added a call to the random number generator.

comment:2 Changed 2 months ago by gkronber

r17491: fix reproducability by calling the PRNG only when probability is < 1

comment:3 Changed 2 months ago by gkronber

  • Status changed from new to accepted
  • Version set to trunk

comment:4 Changed 2 months ago by gkronber

r17492: adapted unit test to compile with r17490

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