Download presentation
Presentation is loading. Please wait.
1
SCHEMATA THEOREM (Holland)
h(i) raw fitness for population sample i f(i) = normalized fitness f(i) = h(i)/Σh(i) A schema denotes a set of substrings that have identical values at certain loci: 1#101 = {10101, 11101} m(S,t) number of scheme exemplars in pop at generation t Number of schema of individual S present in next generation is proportional to chance of an individual being picked that has the schema according to: m(S,t+1) = m(S,t) n f(S)/Σf = m(S,t) f(S)/fave = m(S,t) fave (1+c) m(S,t+1) = m(S,0) (1+c)t Better than average schemata grow exponentially
2
Partially Mapped Crossover
3
Genetic Algorithm cycle
Initial Population Evaluation Selection Elitist strategy Next Generation Crossover Mutation Selected Population Parents Offspring Rank selection Fitness proportional Tournament Make sure that best individual survives
4
Note: In the plot, fitnesses are plotted as (1-R2) and
The problem can be thought as a minimization.
5
Source: A. Yasri and D. Hartsough, Toward an Optimal Procedure for Variable Selection and QSAR Model Building J. Chem. Inf. Comput. Sci Vol. 41, No.5, pp
6
Search space in feature selection
A data set with 10 features
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.