public Node Search()
{
var current = new Node(_myProblem.InitState);
for (;;) //ever
{
//the problem controls what this expands to based on this state
var f = current.Expand(_myProblem);
//hill climbing wants the highest value
var dk = f.ToDictionary(node => _calcValue.Eval(node)).OrderBy(x => x.Key).First();
if (dk.Value == null || dk.Key <= _calcValue.Eval(current))
{
return(current);
}
current = dk.Value;
}
}
public override T Pop()
{
var sortedByHx = _myCollection.ToDictionary(x => _func.Eval(x)).OrderBy(x => x.Key);
var bestByHx = sortedByHx.First().Value;
var theRestByHx = sortedByHx.Skip(1).Take(sortedByHx.Count() - 1);
_myCollection.Clear();
_myCollection.AddRange(theRestByHx.Select(x => x.Value));
return(bestByHx);
}
public Node Search()
{
var current = new Node(_myProblem.InitState);
for (var i = 1; i < int.MaxValue; i++)
{
//this is like lowering the temp slowly from a high in metallurgy
var t = _mySchedule.Eval(i);
if (t.Equals(0.0D))
{
return(current);
}
//expansion of the node is determined by the problem
var expanded = current.Expand(_myProblem).ToList();
if (expanded.Count <= 0)
{
return(current);
}
//choose one at random
var next = expanded[_myRand.Next(0, expanded.Count)];
//sec. 4.1.2 "...picks a random move. If the move improves the situation, it is always accepted.
var deltaE = next.PathCost - current.PathCost;
// Otherwise, the algorithm accepts the move with sonic probability less than 1."
if (deltaE > 0.0D || _myRand.NextDouble() <= Math.Exp(deltaE / t))
{
current = next;
}
/*
* negative scores always have a lower prob. the further they are from
* zero but everyones probablity is shrinking fast anyway.
*
* i t deltaE= -2 deltaE= -1.5 deltaE=-1
* 1 19.11994964 0.900682215 0.924546354 0.949042789
* 2 18.27862371 0.896356175 0.921213855 0.946760886
* 3 17.47431823 0.891853249 0.917740821 0.944379823
* . ... ... ... ...
* 97 0.254293104 0.000383972 0.002742995 0.019595213
* 98 0.243103567 0.000267351 0.002090797 0.016350886
* 99 0.232406397 0.000183075 0.00157388 0.013530518
*/
}
return(current);
}