/// <summary>
/// This fires in an arbitrary thread. It looks at what's in the map, and builds instructions that will be run in the main thread
/// (adds/removes)
/// </summary>
public void Update_AnyThread(double elapsedTime)
{
MapOctree snapshot = _map.LatestSnapshot;
if (snapshot == null)
{
return;
}
IEnumerable <MapObjectInfo> allItems = snapshot.GetItems();
//_map.GetAllItems(true) //TODO: May want to use this to get disposed items
// Look for too few/many
ChangeInstruction[] asteroids = ExamineAsteroids(allItems, _boundry);
ChangeInstruction[] minerals = ExamineMinerals(allItems, _boundry, _mineralTypesByValue);
// Store these instructions for the main thread to do
if (asteroids != null || minerals != null)
{
ChangeInstruction[] instructions = UtilityCore.ArrayAdd(asteroids, minerals);
if (instructions.Length > MAXCHANGES)
{
instructions = UtilityCore.RandomOrder(instructions, MAXCHANGES).ToArray();
}
_instructions = instructions;
}
}
private static SOMResult TrainSOM(SOMNode[] nodes, ISOMInput[] inputs, SOMRules rules, bool returnEmptyNodes = false)
{
double mapRadius = MathND.GetRadius(MathND.GetAABB(nodes.Select(o => o.Weights)));
SOMNode[] returnNodes = nodes.
Select(o => o.Clone()).
ToArray();
double timeConstant = rules.NumIterations / Math.Log(mapRadius);
int iteration = 0;
int remainingIterations = rules.NumIterations;
while (remainingIterations > 0)
{
foreach (ISOMInput input in UtilityCore.RandomOrder(inputs, Math.Min(remainingIterations, inputs.Length)))
{
// Find closest node
SOMNode closest = GetClosest(returnNodes, input).Item1;
// Find other affected nodes (a node and distance squared)
double searchRadius = mapRadius * rules.InitialRadiusPercent * Math.Exp(-iteration / timeConstant);
Tuple <SOMNode, double>[] neigbors = GetNeighbors(returnNodes, closest, searchRadius);
double learningRate = rules.LearningRate * Math.Exp(-(double)iteration / (double)rules.NumIterations);
// Adjust the matched node (full learning rate)
AdjustNodeWeights(closest, input.Weights, learningRate);
foreach (var node in neigbors)
{
double influence = GetInfluence(rules.AttractionFunction, node.Item2, searchRadius);
// Adjust a neighbor
AdjustNodeWeights(node.Item1, input.Weights, learningRate * influence);
}
iteration++;
}
remainingIterations -= inputs.Length;
}
// See which images go with which nodes
ISOMInput[][] inputsByNode = GetInputsByNode(returnNodes, inputs);
SOMResult retVal = new SOMResult(returnNodes, inputsByNode, true);
if (!returnEmptyNodes)
{
retVal = RemoveZeroNodes(retVal);
}
return(retVal);
}