private static void CreateLayerInGraph(ComponentGraph graph, ComponentVertex vertex, RandomNumberGenerator <float> random)
{
if (graph.InDegree(vertex) == 0)
{
// use some arbitrary layout to start
// source layer must be input layer that overrides it
vertex.Layer = Layer.CreateFromArchitecture(new Shape(Shape.BWHC, -1, 100, 100, 100), vertex.Architecture, random);
}
else
{
IList <Shape> shapes = new List <Shape>();
foreach (Edge <ComponentVertex> edge in graph.InEdges(vertex))
{
if (edge.Source.Layer == null)
{
NetworkGraphBuilder.CreateLayerInGraph(graph, edge.Source, random);
}
shapes.Add(edge.Source.Layer.OutputShape);
}
vertex.Layer = shapes.Count == 1 ?
Layer.CreateFromArchitecture(shapes[0], vertex.Architecture, random) :
Layer.CreateFromArchitecture(shapes, vertex.Architecture, random);
}
}
private static void ParseComponents(IList <string> components, out Dictionary <string, string> elements, out Dictionary <string, ComponentGraph> modules)
{
Regex regex = new Regex(@"^(\w+)\s*=\s*(.+)$", RegexOptions.ECMAScript);
elements = new Dictionary <string, string>();
modules = new Dictionary <string, ComponentGraph>();
for (int i = 0; i < components.Count; i++)
{
string component = components[i];
Match match = regex.Match(component);
if (match != null && match.Success && match.Groups.Count == 3)
{
string key = match.Groups[1].Value.Trim();
string value = match.Groups[2].Value.Trim();
if (elements.ContainsKey(key))
{
throw new ArgumentException(
string.Format(CultureInfo.InvariantCulture, Properties.Resources.E_InvalidNetArchitecture_DuplicateVertex, component));
}
if (value.First() == NetworkGraphBuilder.StartQualifier && value.Last() == NetworkGraphBuilder.EndQualifier)
{
modules.Add(key, NetworkGraphBuilder.ParseArchitecture(value.Substring(1, value.Length - 2), true));
}
else
{
elements.Add(key, value);
}
components.RemoveAt(i--);
}
}
}
private static ComponentGraph ParseArchitecture(string architecture, bool isNested)
{
// split architecture into elements that include layers, modules, and edges
IList <string> components = ComponentGraph.SplitArchitecture(architecture, NetworkGraphBuilder.Delimiter);
// extract elements that defines edges and modules (in A=... format)
Dictionary <string, string> elements;
Dictionary <string, ComponentGraph> modules;
NetworkGraphBuilder.ParseComponents(components, out elements, out modules);
// components must now contain edges only (in A-B-... format)
ComponentGraph graph = ComponentGraph.FromComponents(components, elements, modules);
// process nested graphs
if (isNested)
{
// nested graphs must start with a single split layer
IList <ComponentVertex> sources = graph.Sources.ToList();
if (sources.Count > 1)
{
ComponentVertex split = new ComponentVertex(
Guid.NewGuid().ToString(),
string.Format(CultureInfo.InvariantCulture, "SP{0}", sources.Count));
graph.AddEdges(sources.Select(x => new Edge <ComponentVertex>(split, x)));
}
// nested graphs must end with a single concat layer
IList <ComponentVertex> sinks = graph.Sinks.ToList();
if (sinks.Count > 1)
{
ComponentVertex concat = new ComponentVertex(Guid.NewGuid().ToString(), "CONCAT");
graph.AddEdges(sinks.Select(x => new Edge <ComponentVertex>(x, concat)));
}
}
return(graph);
}
public static ComponentGraph FromComponents(IEnumerable <string> components, IDictionary <string, string> elements, IDictionary <string, ComponentGraph> modules)
{
ComponentGraph graph = new ComponentGraph();
Dictionary <string, ComponentVertex> vertices = new Dictionary <string, ComponentVertex>();
foreach (string component in components)
{
IList <string> parts = ComponentGraph.SplitArchitecture(component, NetworkGraphBuilder.Splitter);
if (parts.Count >= 2 && parts.All(x => !string.IsNullOrEmpty(x)))
{
ComponentVertex sourceVertex = null;
ComponentGraph sourceGraph = null;
for (int i = 0, ii = parts.Count; i < ii; i++)
{
string key = parts[i];
ComponentGraph targetGraph = null;
if (key.First() == NetworkGraphBuilder.StartQualifier && key.Last() == NetworkGraphBuilder.EndQualifier)
{
targetGraph = NetworkGraphBuilder.ParseArchitecture(key.Substring(1, key.Length - 2), true);
}
else
{
ComponentGraph moduleGraph;
if (modules.TryGetValue(key, out moduleGraph))
{
targetGraph = moduleGraph.Clone(true) as ComponentGraph;
}
}
if (targetGraph != null)
{
if (i > 0)
{
bool result = sourceVertex != null?ComponentGraph.AddEdge(graph, sourceVertex, targetGraph) : ComponentGraph.AddEdge(graph, sourceGraph, targetGraph);
if (!result)
{
throw new ArgumentException(
string.Format(CultureInfo.InvariantCulture, Properties.Resources.E_InvalidNetArchitecture_DuplicateEdge, parts[i - 1], parts[i]));
}
}
sourceVertex = null;
sourceGraph = targetGraph;
}
else
{
ComponentVertex targetVertex;
string arch;
if (elements.TryGetValue(key, out arch))
{
if (!vertices.TryGetValue(key, out targetVertex))
{
vertices[key] = targetVertex = new ComponentVertex(key, arch);
}
}
else
{
targetVertex = new ComponentVertex(Guid.NewGuid().ToString(), key);
}
if (i > 0)
{
bool result = sourceVertex != null?ComponentGraph.AddEdge(graph, sourceVertex, targetVertex) : ComponentGraph.AddEdge(graph, sourceGraph, targetVertex);
if (!result)
{
throw new ArgumentException(
string.Format(CultureInfo.InvariantCulture, Properties.Resources.E_InvalidNetArchitecture_DuplicateEdge, parts[i - 1], parts[i]));
}
}
sourceVertex = targetVertex;
sourceGraph = null;
}
}
}
else if (parts.Count == 1 && !string.IsNullOrEmpty(parts[0]))
{
graph.AddVertex(new ComponentVertex(Guid.NewGuid().ToString(), parts[0]));
}
else
{
throw new ArgumentException(
string.Format(CultureInfo.InvariantCulture, Properties.Resources.E_InvalidNetArchitecture, component));
}
}
// recreate vertices keys, for the embedded graphs to have unique layers
foreach (ComponentVertex vertex in graph.Vertices)
{
vertex.Key = Guid.NewGuid().ToString();
}
return(graph);
}
public static NetworkGraph CreateNetworkGraph(string architecture, bool addActivationLayers, bool addLossLayer)
{
if (architecture == null)
{
throw new ArgumentNullException(nameof(architecture));
}
if (string.IsNullOrEmpty(architecture))
{
throw new ArgumentException(Properties.Resources.E_InvalidNetArchitecture_NoLayers, nameof(architecture));
}
// 1. parse architecture string and build preliminary graph
ComponentGraph componentGraph = NetworkGraphBuilder.ParseArchitecture(architecture, false);
// 2. create layers in the preliminary graph
RandomNumberGenerator <float> random = null; //// new Random(0);
foreach (ComponentVertex sink in componentGraph.Sinks)
{
NetworkGraphBuilder.CreateLayerInGraph(componentGraph, sink, random);
}
// 3. convert to network graph
NetworkGraph graph = new NetworkGraph();
foreach (Edge <ComponentVertex> edge in componentGraph.Edges)
{
/*NetworkGraph sourceGraph = (edge.Source.Layer as RNNLayer)?.Graph;
* NetworkGraph targetGraph = (edge.Target.Layer as RNNLayer)?.Graph;
*
* if (sourceGraph != null)
* {
* graph.AddGraph(sourceGraph);
* if (targetGraph != null)
* {
* graph.AddEdges(sourceGraph.Sinks, targetGraph.Sources);
* graph.AddGraph(targetGraph);
* }
* else
* {
* graph.AddEdges(sourceGraph.Sinks, edge.Target.Layer);
* }
* }
* else if (targetGraph != null)
* {
* graph.AddEdges(edge.Source.Layer, targetGraph.Sources);
* graph.AddGraph(targetGraph);
* }
* else*/
{
graph.AddEdge(edge.Source.Layer, edge.Target.Layer);
}
}
// 4. add missing loss layers
if (addLossLayer)
{
NetworkGraphBuilder.AddLossLayers(graph);
}
// 5. add missing activation layers
if (addActivationLayers)
{
NetworkGraphBuilder.AddActivationLayers(graph);
}
// 6. initialize stochastic biases with ReLU activations
NetworkGraphBuilder.InitializeReLUs(graph);
return(graph);
}
/// <summary>
/// Creates a classification neural network from a string that contains network architecture.
/// </summary>
/// <param name="architecture">The network architecture.</param>
/// <returns>The <see cref="Network"/> object this method creates.</returns>
public static Network FromArchitecture(string architecture)
{
NetworkGraph graph = NetworkGraphBuilder.CreateNetworkGraph(architecture, true, false);
return(new Network(graph));
}
/// <summary>
/// Creates a classification neural network from a string that contains network architecture.
/// </summary>
/// <param name="architecture">The network architecture.</param>
/// <param name="classes">The classes the network should able to classify into.</param>
/// <param name="allowedClasses">The classes the network is allowed to classify.</param>
/// <param name="blankClass">The blank class that represents none of the real classes.</param>
/// <returns>
/// The <see cref="ClassificationNetwork"/> object this method creates.
/// </returns>
public static ClassificationNetwork FromArchitecture(string architecture, IList <string> classes, IList <string> allowedClasses, string blankClass)
{
NetworkGraph graph = NetworkGraphBuilder.CreateNetworkGraph(architecture, true, true);
return(new ClassificationNetwork(graph, classes, allowedClasses, blankClass));
}