Checkpointing

Checkpoints are supposed to be called perodically (for instance at each generation) and will call every functors you put in them. More...

Classes
class	eoCheckPoint< EOT >
	eoCheckPoint is a container class. More...
Functions
bool	eoCheckPoint< EOT >::operator() (const eoPop< EOT > &_pop)
	The pure virtual function that needs to be implemented by the subclass.
std::string	eoCheckPoint< EOT >::allClassNames () const
	returns a string with all className() of data separated with "\n" (for debugging)

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Detailed Description

Checkpoints are supposed to be called perodically (for instance at each generation) and will call every functors you put in them.

Use them with eoStats, eoUpdater and eoMonitor to get statistics at each generation.

See also:

eoStat

eoMonitor

eoUpdater

Example of a test program using checkpointing:

// to avoid long name warnings
#ifdef _MSC_VER
#pragma warning(disable:4786)
#endif

#include <stdexcept>  // runtime_error

// general
#include <utils/eoRNG.h>                // Random number generators
#include <ga.h>
#include <utils/eoParser.h>
#include <utils/eoState.h>
#include <eoGenContinue.h>

// include package checkpointing
#include <utils/checkpointing>

struct Dummy : public EO<double>
{
    typedef double Type;
};


struct eoDummyPop : public eoPop<Dummy>
{
public :
    eoDummyPop(int s = 2) { resize(s); }
};


int the_main(int argc, char **argv)
{ // ok, we have a command line parser and a state

    typedef eoBit<float> Chrom;

    eoParser parser(argc, argv);

    // Define Parameters
    eoValueParam<double> rate(0.01, "mutationRatePerBit", "Initial value for mutation rate per bit");
    eoValueParam<double> factor(0.99, "mutationFactor", "Decrease factor for mutation rate");
    eoValueParam<uint32_t> seed(time(0), "seed", "Random number seed");
    eoValueParam<std::string> load_name("", "Load","Load",'L');
    eoValueParam<std::string> save_name("", "Save","Save",'S');

    // Register them
    parser.processParam(rate,       "Genetic Operators");
    parser.processParam(factor,     "Genetic Operators");
    parser.processParam(load_name,  "Persistence");
    parser.processParam(save_name,  "Persistence");
    parser.processParam(seed,       "Rng seeding");

   eoState state;
   state.registerObject(parser);

   if (load_name.value() != "")
   { // load the parser. This is only neccessary when the user wants to
     // be able to change the parameters in the state file by hand.
       state.load(load_name.value()); // load the parser
   }

    // Create the algorithm here
    typedef Dummy EoType;

    eoDummyPop pop;

    eoGenContinue<EoType> genTerm(5); // run for 5 generations

    eoCheckPoint<EoType> checkpoint(genTerm);
    // The algorithm will now quit after five generations

    // Create a counter parameter
    eoValueParam<unsigned> generationCounter(0, "Generation");

    // Create an incrementor (wich is an eoUpdater). Note that the
    // Parameter's value is passed by reference, so every time the incrementer increments,
    // the data in generationCounter will change.
    eoIncrementor<unsigned> increment(generationCounter.value());

    // Add it to the checkpoint, this will result in the counter being incremented every generation
    checkpoint.add(increment);

    // The file monitor will print parameters to a comma seperated file
    eoFileMonitor monitor("monitor.csv");

    // the checkpoint mechanism can handle multiple monitors
    checkpoint.add(monitor);

    // the monitor can monitor parameters such as the generationCounter
    monitor.add(generationCounter);

    // Second moment stats: average and stdev
    eoSecondMomentStats<EoType> stats;

    // Add it to the checkpoint to get it called at the appropriate time
    checkpoint.add(stats);

    // Add it to the monitor to get it written to the file
    monitor.add(stats);

    // save state every third generation
    eoCountedStateSaver stateSaver1(3, state, "generation");
    // save state every 2 seconds
    eoTimedStateSaver   stateSaver2(2, state, "time");

    // And add the two savers to the checkpoint
    checkpoint.add(stateSaver1);
    checkpoint.add(stateSaver2);

    // Register the algorithm
    state.registerObject(rng);
    state.registerObject(pop);

    if (parser.userNeedsHelp())
    {
        parser.printHelp(std::cout);
        return 0;
    }

    // Either load or initialize
    if (load_name.value() != "")
    {
        state.load(load_name.value()); // load the rest
    }
    else
    {
        // else

        // initialize rng and population

        rng.reseed(seed.value());

        pop.resize(2);

        pop[0].fitness(1);
        pop[1].fitness(2);
    }

    while(checkpoint(pop))
    {
        pop[0].fitness(pop[0].fitness() + 1);

        time_t now = time(0);

        while (time(0) == now) {} // wait a second to test timed saver

        std::cout << "gen " << generationCounter.value() << std::endl;
    }

    // run the algorithm

    // Save when needed
    if (save_name.value() != "")
    {
        std::string file_name = save_name.value();
        save_name.value() = ""; // so that it does not appear in the parser section of the state file
        state.save(file_name);
    }

    return 1;
}

int main(int argc, char **argv)
{
    try
    {
        the_main(argc, argv);
    }
    catch(std::exception& e)
    {
        std::cout << "Exception: " << e.what() << std::endl;
    }

}