/// <summary>
/// Reads a network definition from XML.
/// An activation function library is required to decode the function ID at each node, typically the
/// library is stored alongside the network definition XML and will have already been read elsewhere and
/// passed in here.
/// </summary>
/// <param name="xr">The XmlReader to read from.</param>
/// <param name="activationFnLib">The activation function library used to decode node activation function IDs.</param>
/// <param name="nodeFnIds">Indicates if node activation function IDs should be read. They are required
/// for HyperNEAT genomes but not NEAT</param>
public static NetworkDefinition ReadNetworkDefinition(XmlReader xr, IActivationFunctionLibrary activationFnLib, bool nodeFnIds)
{
// Find <Network>.
XmlIoUtils.MoveToElement(xr, false, __ElemNetwork);
int initialDepth = xr.Depth;
// Find <Nodes>.
XmlIoUtils.MoveToElement(xr, true, __ElemNodes);
// Create a reader over the <Nodes> sub-tree.
int inputNodeCount = 0;
int outputNodeCount = 0;
NodeList nodeList = new NodeList();
using (XmlReader xrSubtree = xr.ReadSubtree())
{
// Re-scan for the root <Nodes> element.
XmlIoUtils.MoveToElement(xrSubtree, false);
// Move to first node elem.
XmlIoUtils.MoveToElement(xrSubtree, true, __ElemNode);
// Read node elements.
do
{
NodeType nodeType = ReadAttributeAsNodeType(xrSubtree, __AttrType);
uint id = XmlIoUtils.ReadAttributeAsUInt(xrSubtree, __AttrId);
int fnId = 0;
double[] auxState = null;
if (nodeFnIds)
{ // Read activation fn ID.
fnId = XmlIoUtils.ReadAttributeAsInt(xrSubtree, __AttrActivationFunctionId);
// Read aux state as comma separated list of real values.
auxState = XmlIoUtils.ReadAttributeAsDoubleArray(xrSubtree, __AttrAuxState);
}
// TODO: Read node aux state data.
NetworkNode node = new NetworkNode(id, nodeType, fnId, auxState);
nodeList.Add(node);
// Track the number of input and output nodes.
switch (nodeType)
{
case NodeType.Input:
inputNodeCount++;
break;
case NodeType.Output:
outputNodeCount++;
break;
}
}while(xrSubtree.ReadToNextSibling(__ElemNode));
}
// Find <Connections>.
XmlIoUtils.MoveToElement(xr, false, __ElemConnections);
// Create a reader over the <Connections> sub-tree.
ConnectionList connList = new ConnectionList();
using (XmlReader xrSubtree = xr.ReadSubtree())
{
// Re-scan for the root <Connections> element.
XmlIoUtils.MoveToElement(xrSubtree, false);
// Move to first connection elem.
string localName = XmlIoUtils.MoveToElement(xrSubtree, true);
if (localName == __ElemConnection)
{ // We have at least one connection.
// Read connection elements.
do
{
uint srcId = XmlIoUtils.ReadAttributeAsUInt(xrSubtree, __AttrSourceId);
uint tgtId = XmlIoUtils.ReadAttributeAsUInt(xrSubtree, __AttrTargetId);
double weight = XmlIoUtils.ReadAttributeAsDouble(xrSubtree, __AttrWeight);
NetworkConnection conn = new NetworkConnection(srcId, tgtId, weight);
connList.Add(conn);
}while(xrSubtree.ReadToNextSibling(__ElemConnection));
}
}
// Move the reader beyond the closing tags </Connections> and </Network>.
do
{
if (xr.Depth <= initialDepth)
{
break;
}
}while(xr.Read());
// Construct and return loaded network definition.
return(new NetworkDefinition(inputNodeCount, outputNodeCount, activationFnLib, nodeList, connList));
}