Monthly Archives: March 2014

26 March 2014

Present: Lee, Tom (scribe), Bill, Charles Ofria

Note: Student travel grants for GECCO are now open for application.

Diversity

  • Charles suggests using (average) Hamming distance of output vectors instead of behavioral diversity to measure the population diversity
    • This will do a better job of measuring the coverage of the phenotypic space (or “trait coverage”)
    • could just sample this, don’t have to compare every pair of individuals

Discussion of co-solvability paper

  • Very related in motivation to lexicase
  • lexicase is mostly different in that it can select individuals that are really bad at a few test cases as long as they are really good at others.
  • Also, co-solvability requires binary test cases, without an obvious way to use on non-binary cases

5 March 2014

Attending: Lee, Tom (scribe), Bill, Omri, Kartik (virtual), Kwaku (virtual)

Z3

Karthik – can probably connect Clojush and Z3 through Java API.

Lexicase Paper Rejection

  • Some possible additions ideas:
    • Investigate how much of pop is let around after each step of lexicase
    • time runs for this paper
  • Lexicase speedup idea: use a lexicase comparator, and then find optimum in population
    • To do this, would need a lexicase comparator that takes 2 individuals (or error vectors) as well as a test case ordering, and returns the individual with better initial cases based on the ordering
    • Then, you can use the comparator to find the “max” (or “min”) of the population – basically, use it with reduce to find best individual for that ordering
    • We should include this as a possibility in paper, but probably not implement it.
  • Thoughts on niching/fitness sharing:
    • We should definitely enhance our discussion with related techniques, but not necessarily implement and compare with them
    • We should clarify how lexicase is different
    • If we find one option that is common and simple, we could try it out if we have time.