/// <summary>Gets base conditionals.</summary>
/// <param name="x">The Matrix to process.</param>
/// <returns>An array of measure.</returns>
private Measure[] GetBaseConditionals(Matrix x)
{
Measure[] features = new Measure[x.Cols];
for (int i = 0; i < features.Length; i++)
{
Property p = Descriptor.At(i);
var f = new Measure
{
Discrete = p.Discrete,
Label = Descriptor.ColumnAt(i),
};
IEnumerable <Statistic> fstats;
if (f.Discrete)
{
fstats = x[i, VectorType.Col].Distinct().OrderBy(d => d)
.Select(d => Statistic.Make(p.Convert(d).ToString(), d, 1));
}
else
{
fstats = x[i, VectorType.Col].Segment(Width)
.Select(d => Statistic.Make(f.Label, d, 1));
}
f.Probabilities = fstats.ToArray();
features[i] = f;
}
return(features);
}
/// <summary>
/// Creates a new deep neural network based on the supplied inputs and layers.
/// </summary>
/// <param name="d">Descriptor object.</param>
/// <param name="X">Training examples</param>
/// <param name="y">Training labels</param>
/// <param name="activationFunction">Activation Function for each output layer.</param>
/// <param name="outputFunction">Ouput Function for each output layer.</param>
/// <param name="hiddenLayers">The intermediary (hidden) layers / ensembles in the network.</param>
/// <returns>A Deep Neural Network</returns>
public static Network Create(this Network network, Descriptor d, Matrix X, Vector y, IFunction activationFunction, IFunction outputFunction = null, params NetworkLayer[] hiddenLayers)
{
// set output to number of choices of available
// 1 if only two choices
int distinct = y.Distinct().Count();
int output = distinct > 2 ? distinct : 1;
// identity function for bias nodes
IFunction ident = new Ident();
// creating input nodes
network.In = new Neuron[X.Cols + 1];
network.In[0] = new Neuron {
Label = "B0", ActivationFunction = ident
};
for (int i = 1; i < X.Cols + 1; i++)
{
network.In[i] = new Neuron {
Label = d.ColumnAt(i - 1), ActivationFunction = ident
}
}
;
// creating output nodes
network.Out = new Neuron[output];
for (int i = 0; i < output; i++)
{
network.Out[i] = new Neuron {
Label = Network.GetLabel(i, d), ActivationFunction = activationFunction, OutputFunction = outputFunction
}
}
;
for (int layer = 0; layer < hiddenLayers.Count(); layer++)
{
if (layer == 0 && hiddenLayers[layer].IsAutoencoder)
{
// init and train it.
}
// connect input with previous layer or input layer
// connect last layer with output layer
}
// link input to hidden. Note: there are
// no inputs to the hidden bias node
//for (int i = 1; i < h.Length; i++)
// for (int j = 0; j < nn.In.Length; j++)
// Edge.Create(nn.In[j], h[i]);
//// link from hidden to output (full)
//for (int i = 0; i < nn.Out.Length; i++)
// for (int j = 0; j < h.Length; j++)
// Edge.Create(h[j], nn.Out[i]);
return(network);
}
/// <summary>Defaults.</summary>
/// <param name="network">The network.</param>
/// <param name="d">The Descriptor to process.</param>
/// <param name="x">The Vector to process.</param>
/// <param name="y">The Vector to process.</param>
/// <param name="activationFunction">The activation.</param>
/// <param name="outputFunction">The ouput function for hidden nodes (Optional).</param>
/// <param name="epsilon">epsilon</param>
/// <returns>A Network.</returns>
public static Network Create(
this Network network,
Descriptor d,
Matrix x,
Vector y,
IFunction activationFunction,
IFunction outputFunction = null,
double epsilon = double.NaN)
{
// set output to number of choices of available
// 1 if only two choices
var distinct = y.Distinct().Count();
var output = distinct > 2 ? distinct : 1;
// identity funciton for bias nodes
IFunction ident = new Ident();
// set number of hidden units to (Input + Hidden) * 2/3 as basic best guess.
var hidden = (int)System.Math.Ceiling((x.Cols + output) * 2.0 / 3.0);
return(network.Create(
x.Cols,
output,
activationFunction,
outputFunction,
fnNodeInitializer: (l, i) =>
{
if (l == 0)
{
return new Neuron(false)
{
Label = d.ColumnAt(i - 1),
ActivationFunction = activationFunction,
NodeId = i,
LayerId = l
}
}
;
if (l == 2)
{
return new Neuron(false)
{
Label = Network.GetLabel(i, d),
ActivationFunction = activationFunction,
NodeId = i,
LayerId = l
}
}
;
return new Neuron(false)
{
ActivationFunction = activationFunction, NodeId = i, LayerId = l
};
},
hiddenLayers: hidden));
}
/// <summary>Defaults.</summary>
/// <param name="d">The Descriptor to process.</param>
/// <param name="x">The Vector to process.</param>
/// <param name="y">The Vector to process.</param>
/// <param name="activation">The activation.</param>
/// <returns>A Network.</returns>
public static Network Default(Descriptor d, Matrix x, Vector y, IFunction activation)
{
Network nn = new Network();
// set output to number of choices of available
// 1 if only two choices
int distinct = y.Distinct().Count();
int output = distinct > 2 ? distinct : 1;
// identity funciton for bias nodes
IFunction ident = new Ident();
// set number of hidden units to (Input + Hidden) * 2/3 as basic best guess.
int hidden = (int)System.Math.Ceiling((decimal)(x.Cols + output) * 2m / 3m);
// creating input nodes
nn.In = new Node[x.Cols + 1];
nn.In[0] = new Node { Label = "B0", Activation = ident };
for (int i = 1; i < x.Cols + 1; i++)
nn.In[i] = new Node { Label = d.ColumnAt(i - 1), Activation = ident };
// creating hidden nodes
Node[] h = new Node[hidden + 1];
h[0] = new Node { Label = "B1", Activation = ident };
for (int i = 1; i < hidden + 1; i++)
h[i] = new Node { Label = String.Format("H{0}", i), Activation = activation };
// creating output nodes
nn.Out = new Node[output];
for (int i = 0; i < output; i++)
nn.Out[i] = new Node { Label = GetLabel(i, d), Activation = activation };
// link input to hidden. Note: there are
// no inputs to the hidden bias node
for (int i = 1; i < h.Length; i++)
for (int j = 0; j < nn.In.Length; j++)
Edge.Create(nn.In[j], h[i]);
// link from hidden to output (full)
for (int i = 0; i < nn.Out.Length; i++)
for (int j = 0; j < h.Length; j++)
Edge.Create(h[j], nn.Out[i]);
return nn;
}
/// <summary>Defaults.</summary>
/// <param name="d">The Descriptor to process.</param>
/// <param name="x">The Vector to process.</param>
/// <param name="y">The Vector to process.</param>
/// <param name="activationFunction">The activation.</param>
/// <param name="outputFunction">The ouput function for hidden nodes (Optional).</param>
/// <param name="epsilon">epsilon</param>
/// <returns>A Network.</returns>
public static Network Create(this Network network, Descriptor d, Matrix x, Vector y, IFunction activationFunction, IFunction outputFunction = null,
double epsilon = double.NaN, ILossFunction lossFunction = null)
{
// set output to number of choices of available
// 1 if only two choices
int distinct = y.Distinct().Count();
int output = distinct > 2 ? distinct : 1;
// identity funciton for bias nodes
IFunction ident = new Ident();
// set number of hidden units to (Input + Hidden) * 2/3 as basic best guess.
int hidden = (int)System.Math.Ceiling((double)(x.Cols + output) * 2.0 / 3.0);
return(network.Create(x.Cols, output, activationFunction, outputFunction,
fnNodeInitializer: new Func <int, int, NodeType, Neuron>((l, i, type) =>
{
if (type == NodeType.Input)
{
return new Neuron(false)
{
Label = d.ColumnAt(i - 1), ActivationFunction = activationFunction, NodeId = i, LayerId = l
}
}
;
else if (type == NodeType.Output)
{
return new Neuron(false)
{
Label = Network.GetLabel(i, d), ActivationFunction = activationFunction, NodeId = i, LayerId = l
}
}
;
else
{
return new Neuron(false)
{
ActivationFunction = activationFunction, NodeId = i, LayerId = l
}
};
}), lossFunction: lossFunction, hiddenLayers: hidden));
}
/// <summary>Defaults.</summary>
/// <param name="d">The Descriptor to process.</param>
/// <param name="x">The Vector to process.</param>
/// <param name="y">The Vector to process.</param>
/// <param name="activationFunction">The activation.</param>
/// <param name="outputFunction">The ouput function for hidden nodes (Optional).</param>
/// <param name="epsilon">epsilon</param>
/// <returns>A Network.</returns>
public static Network Create(this Network network, Descriptor d, Matrix x, Vector y, IFunction activationFunction, IFunction outputFunction = null, double epsilon = double.NaN)
{
// set output to number of choices of available
// 1 if only two choices
int distinct = y.Distinct().Count();
int output = distinct > 2 ? distinct : 1;
// identity funciton for bias nodes
IFunction ident = new Ident();
// set number of hidden units to (Input + Hidden) * 2/3 as basic best guess.
int hidden = (int)System.Math.Ceiling((double)(x.Cols + output) * 2.0 / 3.0);
return network.Create(x.Cols, output, activationFunction, outputFunction,
fnNodeInitializer: new Func<int, int, Neuron>((l, i) =>
{
if (l == 0) return new Neuron(false) { Label = d.ColumnAt(i - 1), ActivationFunction = activationFunction, NodeId = i, LayerId = l };
else if (l == 2) return new Neuron(false) { Label = Network.GetLabel(i, d), ActivationFunction = activationFunction, NodeId = i, LayerId = l };
else return new Neuron(false) { ActivationFunction = activationFunction, NodeId = i, LayerId = l };
}), hiddenLayers: hidden);
}
/// <summary>
/// Creates a new deep neural network based on the supplied inputs and layers.
/// </summary>
/// <param name="d">Descriptor object.</param>
/// <param name="X">Training examples</param>
/// <param name="y">Training labels</param>
/// <param name="activationFunction">Activation Function for each output layer.</param>
/// <param name="outputFunction">Ouput Function for each output layer.</param>
/// <param name="hiddenLayers">The intermediary (hidden) layers / ensembles in the network.</param>
/// <returns>A Deep Neural Network</returns>
public static Network Create(this Network network, Descriptor d, Matrix X, Vector y, IFunction activationFunction, IFunction outputFunction = null, params NetworkLayer[] hiddenLayers)
{
// set output to number of choices of available
// 1 if only two choices
int distinct = y.Distinct().Count();
int output = distinct > 2 ? distinct : 1;
// identity function for bias nodes
IFunction ident = new Ident();
// creating input nodes
network.In = new Neuron[X.Cols + 1];
network.In[0] = new Neuron { Label = "B0", ActivationFunction = ident };
for (int i = 1; i < X.Cols + 1; i++)
network.In[i] = new Neuron { Label = d.ColumnAt(i - 1), ActivationFunction = ident };
// creating output nodes
network.Out = new Neuron[output];
for (int i = 0; i < output; i++)
network.Out[i] = new Neuron { Label = Network.GetLabel(i, d), ActivationFunction = activationFunction, OutputFunction = outputFunction };
for (int layer = 0; layer < hiddenLayers.Count(); layer++)
{
if (layer == 0 && hiddenLayers[layer].IsAutoencoder)
{
// init and train it.
}
// connect input with previous layer or input layer
// connect last layer with output layer
}
// link input to hidden. Note: there are
// no inputs to the hidden bias node
//for (int i = 1; i < h.Length; i++)
// for (int j = 0; j < nn.In.Length; j++)
// Edge.Create(nn.In[j], h[i]);
//// link from hidden to output (full)
//for (int i = 0; i < nn.Out.Length; i++)
// for (int j = 0; j < h.Length; j++)
// Edge.Create(h[j], nn.Out[i]);
return network;
}
/// <summary>Builds a tree.</summary>
/// <param name="x">The Matrix to process.</param>
/// <param name="y">The Vector to process.</param>
/// <param name="depth">The depth.</param>
/// <param name="used">The used.</param>
/// <returns>A Node.</returns>
private Node BuildTree(Matrix x, Vector y, int depth, List <int> used, Tree tree)
{
if (depth < 0)
{
return(BuildLeafNode(y.Mode()));
}
var tuple = GetBestSplit(x, y, used);
var col = tuple.Item1;
var gain = tuple.Item2;
var measure = tuple.Item3;
// uh oh, need to return something?
// a weird node of some sort...
// but just in case...
if (col == -1)
{
return(BuildLeafNode(y.Mode()));
}
used.Add(col);
Node node = new Node
{
Column = col,
Gain = gain,
IsLeaf = false,
Name = Descriptor.ColumnAt(col)
};
// populate edges
List <Edge> edges = new List <Edge>(measure.Segments.Length);
for (int i = 0; i < measure.Segments.Length; i++)
{
// working set
var segment = measure.Segments[i];
var edge = new Edge()
{
ParentId = node.Id,
Discrete = measure.Discrete,
Min = segment.Min,
Max = segment.Max
};
IEnumerable <int> slice;
if (edge.Discrete)
{
// get discrete label
edge.Label = Descriptor.At(col).Convert(segment.Min).ToString();
// do value check for matrix slicing
slice = x.Indices(v => v[col] == segment.Min);
}
else
{
// get range label
edge.Label = string.Format("{0} <= x < {1}", segment.Min, segment.Max);
// do range check for matrix slicing
slice = x.Indices(v => v[col] >= segment.Min && v[col] < segment.Max);
}
// something to look at?
// if this number is 0 then this edge
// leads to a dead end - the edge will
// not be built
if (slice.Count() > 0)
{
Vector ySlice = y.Slice(slice);
// only one answer, set leaf
if (ySlice.Distinct().Count() == 1)
{
var child = BuildLeafNode(ySlice[0]);
tree.AddVertex(child);
edge.ChildId = child.Id;
}
// otherwise continue to build tree
else
{
var child = BuildTree(x.Slice(slice), ySlice, depth - 1, used, tree);
tree.AddVertex(child);
edge.ChildId = child.Id;
}
edges.Add(edge);
}
}
// problem, need to convert
// parent to terminal node
// with mode
if (edges.Count <= 1)
{
var val = y.Mode();
node.IsLeaf = true;
node.Value = val;
}
tree.AddVertex(node);
if (edges.Count > 1)
{
foreach (var e in edges)
{
tree.AddEdge(e);
}
}
return(node);
}
/// <summary>Defaults.</summary>
/// <param name="d">The Descriptor to process.</param>
/// <param name="x">The Vector to process.</param>
/// <param name="y">The Vector to process.</param>
/// <param name="activation">The activation.</param>
/// <returns>A Network.</returns>
public static Network Default(Descriptor d, Matrix x, Vector y, IFunction activation)
{
var nn = new Network();
// set output to number of choices of available
// 1 if only two choices
var distinct = y.Distinct().Count();
var output = distinct > 2 ? distinct : 1;
// identity funciton for bias nodes
IFunction ident = new Ident();
// set number of hidden units to (Input + Hidden) * 2/3 as basic best guess.
var hidden = (int)Math.Ceiling((decimal)(x.Cols + output) * 2m / 3m);
// creating input nodes
nn.In = new Node[x.Cols + 1];
nn.In[0] = new Node {
Label = "B0", Activation = ident
};
for (var i = 1; i < x.Cols + 1; i++)
{
nn.In[i] = new Node {
Label = d.ColumnAt(i - 1), Activation = ident
};
}
// creating hidden nodes
var h = new Node[hidden + 1];
h[0] = new Node {
Label = "B1", Activation = ident
};
for (var i = 1; i < hidden + 1; i++)
{
h[i] = new Node {
Label = string.Format("H{0}", i), Activation = activation
};
}
// creating output nodes
nn.Out = new Node[output];
for (var i = 0; i < output; i++)
{
nn.Out[i] = new Node {
Label = GetLabel(i, d), Activation = activation
};
}
// link input to hidden. Note: there are
// no inputs to the hidden bias node
for (var i = 1; i < h.Length; i++)
{
for (var j = 0; j < nn.In.Length; j++)
{
Edge.Create(nn.In[j], h[i]);
}
}
// link from hidden to output (full)
for (var i = 0; i < nn.Out.Length; i++)
{
for (var j = 0; j < h.Length; j++)
{
Edge.Create(h[j], nn.Out[i]);
}
}
return(nn);
}
