variables.hpp

/*
   A Library for Particle Swarm Optimization

   Copyright 2015 Raghav Dua, Mridul Bhambri
   
   This program is free software: you can redistribute it and/or
   modify it under the terms of the GNU General Public License version
   3 as published by the Free Software Foundation.
   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see
   <http://www.gnu.org/licenses/>.
 */

#include "includes.hpp"

/*
   Declaration & Description of Variables and structures used in the library
*/

namespace pso {
	/*
		Strategy constants for Social Factor Influence
	*/
	const unsigned int STRATEGY_GLOBAL (0);
	const unsigned int STRATEGY_KNN (1);
	const double NEIGHBOUR_FRACTION (0.35);

	/*
		Constants for Inertia Weight Configuration 
	*/
	const double DEFAULT_W (0.6359);
	const double DEFAULT_W_HI (0.9);
	const double DEFAULT_W_LO (0.4);
	const unsigned int STRATEGY_W_CONST (0);
	const unsigned int STRATEGY_W_LIN_DEC (1);

	/*
		Constants for determining Halting Conditions - Can be used in combination with each-other using bitwise OR '|' operator
		EXAMPLE: pso.halt_strategy = STRATEGY_FITNESS_THRESHOLD | STRATEGY_ITER_LIMIT;		
		//loop breaks if error is small enough or N iterations have passed
	*/
	const double MAX_ERR = std::numeric_limits< double >::max ();
	const double DEFAULT_ERR_THRESHOLD (1e-03);
	const unsigned int DEFAULT_ITERATIONS (5000);
	const unsigned int DEFAULT_NO_IMPROVE_ITER (100);

	const unsigned int STRATEGY_FITNESS_THRESHOLD (1);
	const unsigned int STRATEGY_ITER_LIMIT (2);
	const unsigned int STRATEGY_NO_IMPROVE (3);

	/*
		Constants concerning the Swarm
	*/
	const unsigned int SWARM_SIZE_MAX (100);

	/*
		Cognitive & Social Constants
		C1 = C2 = C (defined below)
	*/
	const double C (1.496);

	/*
		Constants for Verbose Information
	*/
	const unsigned int VERBOSE_OFF (false);
	const unsigned int VERBOSE_ON (true);

	/*
		Constants for Database Storage
	*/
	const unsigned int DB_STORE_OFF (false);
	const unsigned int DB_STORE_ON (true);

	/*
		Exception Descriptions (pso.hpp)
	*/
	const char *ex_strategy_social = "Bad value for Social Strategy (should be either pso::STRATEGY_GLOBAL or pso::STRATEGY_KNN)";
	const char *ex_knn_large = "Number of neighbours cannot be larger than the Swarm Size";
	const char *ex_knn_small = "Number of neighbours cannot be smaller than 1";
	const char *ex_weight = "Bad value for Inertia Weight Strategy (should be either pso::STRATEGY_W_LIN_DEC or pso::STRATEGY_W_CONST)";
	const char *ex_err_thresh = "Error Threshold cannot be negative";
	const char *ex_iter_max = "Iteration Limit cannot be negative";
	const char *ex_no_improve_count = "No-Improve-Count cannot be smaller than 1";
	const char *ex_swarm_size_large = "Integer too large for Swarm Size (can be at most pso::SWARM_SIZE_MAX)";
	const char *ex_swarm_size_small = "Integer too small for Swarm Size (must be at least 1)";
	const char *ex_iw_lo_bigger = "Lower Bound of Inertia Weight Cannot be bigger than the Upper bound. usage: set_iw_bounds (lower, upper)";

	/*
		Exception Descriptions (db_connection.hpp)
	*/
	const char *ex_db_init_fail = "Database Object Initialization Failed";
	const char *ex_db_connection_fail = "Database Connection Failed";
	const char *ex_insufficient_data = "The Credentials / Database Name has(ve) not been provided";
};