The GA Procedure

Cross Call

call Cross ( selected, seg, type<, parameter1, parameter2, …> ) ;

The Cross call executes a genetic crossover operator from within a user subroutine. The inputs to the subroutine are as follows:

selected	is an array that specifies the solutions to be crossed.
seg	is the desired segment of the solution to which the crossover operator should be applied.
type	is the type of crossover operator to apply, which also determines the number and type of parameters expected.
parameter1-n	are optional parameters applicable to some operators.

The accepted values for type and the corresponding parameters are summarized in Table 3.1.

Table 3.1: Crossover Operator Types

Type	Encodings	Parameters
'arithmetic'	real, integer
'cycle'	sequence
'heuristic'	real
'null'	all encodings
'order'	sequence
'pmatch'	sequence
'simple'	real, integer, Boolean	alpha
'twopoint'	real, integer, Boolean	alpha
'uniform'	real, integer, Boolean	alpha, p

The parameters are as follows:

alpha	is a number such that $0 < alpha \leq 1$ .
p	is a probability such that $0 < p \leq 0.5$ .

The Cross call should be made only from within a user crossover subroutine. The precise action of these crossover operators is described in the section Crossover Operators.