public void ComputeTwiceGradientShouldYieldTheSameResult()
{
const int inputWidth = 20;
const int inputHeight = 20;
const int inputDepth = 2;
var layer = new ReluLayer();
layer.Init(inputWidth, inputHeight, inputDepth);
// Forward pass
var input = BuilderInstance.Volume.Random(new Shape(inputWidth, inputHeight, inputDepth));
var output = layer.DoForward(input, true);
// Set output gradients to 1
var outputGradient = BuilderInstance.Volume.SameAs(new double[output.Shape.TotalLength].Populate(1.0), output.Shape);
// Backward pass to retrieve gradients
layer.Backward(outputGradient);
var step1 = ((Volume.Double.Volume)layer.InputActivationGradients.Clone()).ToArray();
layer.Backward(outputGradient);
var step2 = ((Volume.Double.Volume)layer.InputActivationGradients.Clone()).ToArray();
Assert.IsTrue(step1.SequenceEqual(step2));
}
