public override NDarray <U> Backward(NDarray <U> accumGrad)
{
wT.SetContent(weights.T.Evaluate());
agBw.SetContent(accumGrad);
if (IsTraining)
{
var gw = gwExpr.Evaluate();
var gb = gbExpr.Evaluate();
weights.SetContent(wOpt.Update(weights.Evaluate(), gw));
biases.SetContent(bOpt.Update(biases.Evaluate(), gb));
}
return(bwExpr.Evaluate());
}
static void Main(string[] args)
{
Operations K = new Operations();
//Load array to the tensor
NDArray x = new NDArray(3, 3);
x.Load(2, 4, 6, 1, 3, 5, 2, 3, 5);
x.Print("Load X Values");
NDArray y = new NDArray(3, 1);
y.Load(1, 0, 1);
y.Print("Load Y Values");
//Create two layers, one with 6 neurons and another with 1
FullyConnected fc1 = new FullyConnected(3, 6, "relu");
FullyConnected fc2 = new FullyConnected(6, 1, "sigmoid");
//Connect input by passing data from one layer to another
fc1.Forward(x);
fc2.Forward(fc1.Output);
var preds = fc2.Output;
preds.Print("Predictions");
//Calculate the mean square error cost between the predicted and expected values
BaseCost cost = new BinaryCrossEntropy();
var costValues = cost.Forward(preds, y);
costValues.Print("BCE Cost");
//Calculate the mean absolute metric value for the predicted vs expected values
BaseMetric metric = new BinaryAccuacy();
var metricValues = metric.Calculate(preds, y);
metricValues.Print("Acc Metric");
var grad = cost.Backward(preds, y);
fc2.Backward(grad);
fc1.Backward(fc2.InputGrad);
Console.WriteLine("Param value for FC1 before ADAM optimization");
fc1.PrintParams(printGrads: false);
//Initialise ADAM optimizer with default learning rate of 0.01
BaseOptimizer optimizer = BaseOptimizer.Get("adam");
//Change the value of learning rate to see the jump is weight changes.
//optimizer.LearningRate = 0.1;
//Apply optimizer for the first layer for first iteration
optimizer.Update(1, fc1);
Console.WriteLine("Param value for FC1 after ADAM optimization");
fc1.PrintParams(printGrads: false);
Console.WriteLine("Param value for FC2 before ADAM optimization");
fc2.PrintParams(printGrads: false);
//Apply optimizer for the first layer for first iteration
optimizer.Update(1, fc2);
Console.WriteLine("Param value for FC2 after ADAM optimization");
fc2.PrintParams(printGrads: false);
Console.ReadLine();
}