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User Manual | Methods | Optimization Methods | Evolutionary Programming

Evolutionary Programming

Evolutionary programming (EP) [Fogel92 Baeck93 Baeck97] is a computational technique that mimics evolution and is based on reproduction and selection. An EP algorithm is composed of individuals that reproduce and compete, each one is a potential solution to the (optimization) problem and is represented by a "genome" where each gene corresponds to one adjustable parameter. At each generation of the EP, each individual reproduces asexually, i.e. divides into two individuals. One of these contains exactly the same "genome" as the parent while the other suffers some mutations (the parameter values of each gene change slightly). At the end of the generation, the algorithm has double the number of individuals. Then each of the individuals is confronted with a number of others to count how many does it outperform (the number of wins is the number of these competitors that represent worse solutions than itself). All the individuals are ranked by their number of wins, and the population is again reduced to the original number of individuals by eliminating those which have worse fitness (solutions).

Options for Evolutionary Programming

Number of Generations
The parameter is a positive integer value to determine the number of generations the algorithm shall evolve the population. The default is '200'.

Population Size
The parameter is a positive integer value to determine the size of the population, i.e., the number of individuals that survive after each generation. The default is '20'. Random Number Generator The parameter is an enumeration value to determine which random number generator this method shall use. COPASI provides two random number generators R250 [Maier91] (selected through the value 0) and the Mersenne Twister [Matsumoto98] (selected through the value 1 (default)).

The parameter is a positive integer value to determine the seed for the random number generator. A value of zero instructs COPASI to select a "random" value.