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  Topic: Evolutionary Computation, Stuff that drives AEs nuts< Next Oldest | Next Newest >  
Zachriel



Posts: 2723
Joined: Sep. 2006

(Permalink) Posted: June 17 2009,20:59   

Some bits from Mendel's Accountant source code.

Offspring:

if(fitness_dependent_fertility) then
              fitness_adjusted_offspring = num_offspring*sqrt(post_sel_fitness)


Favorable Mutations:

c...  Compute mean absolute fitness effect for favorable mutations.

     sum = 0.
     d2  = 1.

     do i=1,1000000
        d1 = d2
        d2 = exp(-alpha_fav*(0.000001*i)**gamma_fav)
        sum = sum + d1 + d2
     end do

     fav_mean = 0.0000005*sum*max_fav_fitness_gain


Phenotypic Fitness:

     noise = sqrt(geno_fitness_variance*(1. - heritability) /heritability + non_scaling_noise**2)

c...  Add noise to the fitness to create a phenotypic fitness score...
do i=1,total_offspring
        pheno_fitness(i) = fitness(i) + random_normal()*noise


Unrestricted probability selection:

c...     For unrestricted probability selection, divide the phenotypic  
c...     fitness by a uniformly distributed random number prior to
c...     ranking and truncation.  This procedure allows the probability
c...     of surviving and reproducing in the next generation to be
c...     directly related to phenotypic fitness and also for the correct
c...     number of individuals to be eliminated to maintain a constant
c...     population size.

        do i=1,total_offspring
           work_fitness(i) = work_fitness(i)/(randomnum(1) + 1.d-15)
        end do


Divide by randomnum as well as add non-heritable noise to the phenotype?

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You never step on the same tard twice—for it's not the same tard and you're not the same person.

   
  419 replies since Mar. 17 2009,11:00 < Next Oldest | Next Newest >  

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