public void ConnectThroughInput()
{
// Simple acyclic graph.
var connList = new List <DirectedConnection>
{
new DirectedConnection(0, 3),
new DirectedConnection(1, 3),
new DirectedConnection(2, 3),
new DirectedConnection(2, 4),
new DirectedConnection(4, 1)
};
// Create graph.
connList.Sort();
var digraph = DirectedGraphBuilder.Create(connList, 3, 2);
// Assert is acyclic.
var cyclicGraphAnalysis = new CyclicGraphAnalysis();
Assert.IsTrue(!cyclicGraphAnalysis.IsCyclic(digraph));
// Depth analysis.
GraphDepthInfo depthInfo = AcyclicGraphDepthAnalysis.CalculateNodeDepths(digraph);
// Assertions.
Assert.AreEqual(4, depthInfo._networkDepth);
Assert.AreEqual(5, depthInfo._nodeDepthArr.Length);
// Node depths.
Assert.AreEqual(0, depthInfo._nodeDepthArr[0]);
Assert.AreEqual(2, depthInfo._nodeDepthArr[1]);
Assert.AreEqual(0, depthInfo._nodeDepthArr[2]);
Assert.AreEqual(3, depthInfo._nodeDepthArr[3]);
Assert.AreEqual(1, depthInfo._nodeDepthArr[4]);
}
/// <summary>
/// Create a NeatGenome with the given meta data, connection genes and supplementary data.
/// </summary>
/// <param name="id">Genome ID.</param>
/// <param name="birthGeneration">Birth generation.</param>
/// <param name="connGenes">Connection genes.</param>
/// <param name="hiddenNodeIdArr">An array of the hidden node IDs in the genome, in ascending order.</param>
/// <returns>A new NeatGenome instance.</returns>
public NeatGenome <T> Create(
int id, int birthGeneration,
ConnectionGenes <T> connGenes,
int[] hiddenNodeIdArr)
{
int inputCount = _metaNeatGenome.InputNodeCount;
int outputCount = _metaNeatGenome.OutputNodeCount;
int inputOutputCount = _metaNeatGenome.InputOutputNodeCount;
// Create a mapping from node IDs to node indexes.
Dictionary <int, int> nodeIdxById = BuildNodeIndexById(hiddenNodeIdArr);
// Create a DictionaryNodeIdMap.
DictionaryNodeIdMap nodeIndexByIdMap = new DictionaryNodeIdMap(inputCount, nodeIdxById);
// Create a digraph from the genome.
DirectedGraph digraph = NeatGenomeBuilderUtils.CreateDirectedGraph(
_metaNeatGenome, connGenes, nodeIndexByIdMap);
// Calc the depth of each node in the digraph.
GraphDepthInfo depthInfo = _graphDepthAnalysis.CalculateNodeDepths(digraph);
// Create a weighted acyclic digraph.
// Note. This also outputs connectionIndexMap. For each connection in the acyclic graph this gives
// the index of the same connection in the genome; this is because connections are re-ordered based
// on node depth in the acyclic graph.
AcyclicDirectedGraph acyclicDigraph = AcyclicDirectedGraphBuilderUtils.CreateAcyclicDirectedGraph(
digraph,
depthInfo,
out int[] newIdByOldId,
out int[] connectionIndexMap,
ref _timesortWorkArr,
ref _timesortWorkVArr);
// TODO: Write unit tests to cover this!
// Update nodeIdxById with the new depth based node index allocations.
// Notes.
// The current nodeIndexByIdMap maps node IDs (also know as innovation IDs in NEAT) to a compact
// ID space in which any gaps have been removed, i.e. a compacted set of IDs that can be used as indexes,
// i.e. if there are N nodes in total then the highest node ID will be N-1.
//
// Here we map the new compact IDs to an alternative ID space that is also compact, but ensures that nodeIDs
// reflect the depth of a node in the acyclic graph.
UpdateNodeIndexById(nodeIdxById, hiddenNodeIdArr, newIdByOldId);
// Create the neat genome.
return(new NeatGenome <T>(
_metaNeatGenome, id, birthGeneration,
connGenes,
hiddenNodeIdArr,
nodeIndexByIdMap,
acyclicDigraph,
connectionIndexMap));
}
public void TestAddAcyclicConnection_CumulativeAdditions()
{
var pop = CreateNeatPopulation();
var genomeBuilder = NeatGenomeBuilderFactory <double> .Create(pop.MetaNeatGenome);
var rootGenome = pop.GenomeList[0];
var strategy = new AddAcyclicConnectionStrategy <double>(
pop.MetaNeatGenome, genomeBuilder,
pop.GenomeIdSeq, pop.InnovationIdSeq, pop.GenerationSeq);
IRandomSource rng = RandomDefaults.CreateRandomSource();
var nodeIdSet = GetNodeIdSet(rootGenome);
CyclicGraphAnalysis cyclicGraphAnalysis = new CyclicGraphAnalysis();
AcyclicGraphDepthAnalysis graphDepthAnalysis = new AcyclicGraphDepthAnalysis();
// Run the inner loop test multiple times.
// Note. The add-connection mutations are random, thus each loop accumulates a different set of mutations.
for (int i = 0; i < 50; i++)
{
var parentGenome = rootGenome;
// Accumulate random mutations for some number of loops.
for (int j = 0; j < 20;)
{
var childGenome = strategy.CreateChildGenome(rootGenome, rng);
// Note. the strategy will return a null if it cannot find an acyclic connection to add;
// test for this and try again. The test will be for N successful mutations rather than N attempts.
if (null == childGenome)
{
continue;
}
// The child genome should have one more connection than parent.
Assert.AreEqual(rootGenome.ConnectionGenes.Length + 1, childGenome.ConnectionGenes.Length);
// The child genome's new connection should not be a duplicate of any of the existing/parent connections.
var connSet = GetDirectedConnectionSet(rootGenome);
var childConnSet = GetDirectedConnectionSet(childGenome);
var newConnList = new List <DirectedConnection>(childConnSet.Except(connSet));
Assert.AreEqual(1, newConnList.Count);
// The connection genes should be sorted.
Assert.IsTrue(SortUtils.IsSortedAscending(childGenome.ConnectionGenes._connArr));
// The child genome should have the same set of node IDs as the parent.
var childNodeIdSet = GetNodeIdSet(childGenome);
Assert.IsTrue(nodeIdSet.SetEquals(childNodeIdSet));
// The child genome should describe an acyclic graph, i.e. the new connection should not have
// formed a cycle in the graph.
var digraph = childGenome.DirectedGraph;
Assert.IsFalse(cyclicGraphAnalysis.IsCyclic(digraph));
// Run the acyclic graph depth analysis algorithm.
GraphDepthInfo depthInfo = graphDepthAnalysis.CalculateNodeDepths(childGenome.DirectedGraph);
// Run again with the alternative algorithm (that uses function recursion).
GraphDepthInfo depthInfo2 = AcyclicGraphDepthAnalysisByRecursion.CalculateNodeDepths(childGenome.DirectedGraph);
Assert.AreEqual(nodeIdSet.Count, depthInfo._nodeDepthArr.Length);
Assert.AreEqual(nodeIdSet.Count, depthInfo2._nodeDepthArr.Length);
TestUtils.Compare(depthInfo2._nodeDepthArr, depthInfo._nodeDepthArr);
// Set the child genome to be the new parent, thus we accumulate random new connections over time.
parentGenome = childGenome;
// Increment for successful tests only.
j++;
}
}
}
