/**
* Fitness functions for testing
*
* @package nodeo
* @author J. J. Merelo <jjmerelo@gmail.com>
* @license GPL v3
*/
// To avoid uncomprehensible radix complaint at charAt
/*jshint -W065 */
/*jshint smarttabs:true */
var functions = exports;
//Ackley description in http://tracer.lcc.uma.es/problems/ackley/ackley.html
functions.ackley = function(x) {
var result = 0;
var sum = 0;
console.log("Working with");
console.log(x);
console.log("Checking for " + x.length);
for ( var i in x ) {
sum += x[i]*x[i];
}
result = 20 - 20*Math.exp(-0.2*Math.sqrt(sum/x.length));
var cos = 0;
for ( i in x ) {
cos += Math.cos(2*Math.PI*x[i]);
}
result += Math.E - Math.exp(cos/x.length); // needed for precision
console.log("Result = " + result.toPrecision(6));
return result; // hack for returning 0
};
// L-trap function
functions.ltrap = function(x,l,a,b,z) {
var total = 0;
for ( var i = 0; i < x.length; i+= l ) {
var this_substr = x.substr( i, l );
var num_ones = 0;
for ( var j = 0; j < this_substr.length; j++ ) {
num_ones += (this_substr.substring(j,j+1) === "1");
}
var this_result;
if ( num_ones <= z ) {
this_result = a*(z-num_ones)/z;
} else {
this_result = b*(num_ones -z)/(l-z);
}
total += this_result;
// console.log("Total " + i + " :"+total + " num_ones " + num_ones );
}
return total;
};
//Masive Multimodal Deceptive Problem, a classic test function
functions.MMDP = function(x) {
var block_size = 6;
var unitation = [1,0,0.360384,0.640576,0.360384,0,1];
var total = 0;
for ( var i = 0; i < x.length; i+= block_size ) {
var this_substr = x.substr( i, block_size );
var num_ones = 0;
for ( var j = 0; j < this_substr.length; j++ ) {
num_ones += (this_substr.substring(j,j+1) === "1");
}
total += unitation[num_ones];
}
return total;
};
//Rastrigin function
functions.Rastrigin = function(x) {
var total = 0;
for (var i = 0; i < x.length; i++) {
var value = x[i];
total = total + (value*value) - (10.0*Math.cos(2*Math.PI*value));
}
return total+10*x.length;
}
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