Function PGASetUserFunction

• Defined in File user.c

Function Documentation

void PGASetUserFunction(PGAContext *ctx, int constant, void *f)

Specify the name of a user-written function to provide a specific GA capability (e.g., crossover, mutation, etc.).

Description

This function must be used when using a non-native datatype and must be called once for each of:

• PGA_USERFUNCTION_CREATESTRING – String creation

• PGA_USERFUNCTION_MUTATION – Mutation

• PGA_USERFUNCTION_CROSSOVER – Crossover

• PGA_USERFUNCTION_PRINTSTRING – String Output

• PGA_USERFUNCTION_COPYSTRING – Duplication

• PGA_USERFUNCTION_DUPLICATE – Duplicate Checking

• PGA_USERFUNCTION_GEN_DISTANCE – Genetic Distance

• PGA_USERFUNCTION_INITSTRING – Initialization

• PGA_USERFUNCTION_BUILDDATATYPE – MPI Datatype creation

• PGA_USERFUNCTION_HASH – Hashing of genes

• PGA_USERFUNCTION_CHROM_FREE – Free chromosome

The following need to be defined for serializing strings for transmission:

• PGA_USERFUNCTION_SERIALIZE – Serialize userdefined gene

• PGA_USERFUNCTION_DESERIALIZE – Deserialize userdefined gene

• PGA_USERFUNCTION_SERIALIZE_FREE – Free serialized version

The following functions are always optional:

• PGA_USERFUNCTION_STOPCOND – Stopping conditions

• PGA_USERFUNCTION_ENDOFGEN – Auxiliary functions at the end of each generation

• PGA_USERFUNCTION_PRE_EVAL – Auxiliary functions before evaluation but after crossover and mutation

• PGA_USERFUNCTION_HILLCLIMB – Hillclimbing

Some of these functions may be called when using a native datatype to replace the built-in functions PGAPack has for that datatype (For example, if the Integer data type is used for a traveling salesperson problem, the user may want to provide their own custom crossover operator). See Constants for User Functions for the constants and chapters Custom Usage: Native Data Types (for custom functions used with the builtin data types) and Custom Usage: New Data Types (for defining new data types) in the user guide and the examples in the examples directory for more details.

Example

void MyStringInit (PGAContext *, void *);
PGAContext *ctx;

...
PGASetUserFunction (ctx, PGA_USERFUNCTION_INITSTRING, MyStringInit);

Parameters:

• ctx – context variable

• constant – symbolic constant of the user function to set

• f – name of the function to use

Returns:

None