public Matrix sensitivityMatrixFromSucceedingLayer(
LayerSensitivity nextLayerSensitivity) {
Layer nextLayer = nextLayerSensitivity.getLayer();
Matrix derivativeMatrix = createDerivativeMatrix(layer
.getLastInducedField());
Matrix weightTranspose = nextLayer.getWeightMatrix().transpose();
Matrix calculatedSensitivityMatrix = derivativeMatrix.times(
weightTranspose).times(
nextLayerSensitivity.getSensitivityMatrix());
sensitivityMatrix = calculatedSensitivityMatrix.copy();
return sensitivityMatrix;
}
public Matrix calculateWeightUpdates(LayerSensitivity layerSensitivity,
Vector previousLayerActivationOrInput, double alpha, double momentum)
{
Layer layer = layerSensitivity.getLayer();
Matrix activationTranspose = previousLayerActivationOrInput.transpose();
Matrix momentumLessUpdate = layerSensitivity.getSensitivityMatrix()
.times(activationTranspose).times(alpha).times(-1.0);
Matrix updateWithMomentum = layer.getLastWeightUpdateMatrix().times(
momentum).plus(momentumLessUpdate.times(1.0 - momentum));
layer.acceptNewWeightUpdate(updateWithMomentum.copy());
return updateWithMomentum;
}
public static Matrix calculateWeightUpdates(
LayerSensitivity layerSensitivity,
Vector previousLayerActivationOrInput, double alpha)
{
Layer layer = layerSensitivity.getLayer();
Matrix activationTranspose = previousLayerActivationOrInput.transpose();
Matrix weightUpdateMatrix = layerSensitivity.getSensitivityMatrix()
.times(activationTranspose).times(alpha).times(-1.0);
layer.acceptNewWeightUpdate(weightUpdateMatrix.copy());
return(weightUpdateMatrix);
}
public Matrix calculateWeightUpdates(LayerSensitivity layerSensitivity,
Vector previousLayerActivationOrInput, double alpha, double momentum)
{
Layer layer = layerSensitivity.getLayer();
Matrix activationTranspose = previousLayerActivationOrInput.transpose();
Matrix momentumLessUpdate = layerSensitivity.getSensitivityMatrix()
.times(activationTranspose).times(alpha).times(-1.0);
Matrix updateWithMomentum = layer.getLastWeightUpdateMatrix().times(
momentum).plus(momentumLessUpdate.times(1.0 - momentum));
layer.acceptNewWeightUpdate(updateWithMomentum.copy());
return(updateWithMomentum);
}
public Matrix sensitivityMatrixFromSucceedingLayer(
LayerSensitivity nextLayerSensitivity)
{
Layer nextLayer = nextLayerSensitivity.getLayer();
Matrix derivativeMatrix = createDerivativeMatrix(layer
.getLastInducedField());
Matrix weightTranspose = nextLayer.getWeightMatrix().transpose();
Matrix calculatedSensitivityMatrix = derivativeMatrix.times(
weightTranspose).times(
nextLayerSensitivity.getSensitivityMatrix());
sensitivityMatrix = calculatedSensitivityMatrix.copy();
return(sensitivityMatrix);
}
public static Vector calculateBiasUpdates(
LayerSensitivity layerSensitivity, double alpha)
{
Layer layer = layerSensitivity.getLayer();
Matrix biasUpdateMatrix = layerSensitivity.getSensitivityMatrix()
.times(alpha).times(-1.0);
Vector result = new Vector(biasUpdateMatrix.getRowDimension());
for (int i = 0; i < biasUpdateMatrix.getRowDimension(); i++)
{
result.setValue(i, biasUpdateMatrix.get(i, 0));
}
layer.acceptNewBiasUpdate(result.copyVector());
return(result);
}
public Vector calculateBiasUpdates(LayerSensitivity layerSensitivity,
double alpha, double momentum)
{
Layer layer = layerSensitivity.getLayer();
Matrix biasUpdateMatrixWithoutMomentum = layerSensitivity
.getSensitivityMatrix().times(alpha).times(-1.0);
Matrix biasUpdateMatrixWithMomentum = layer.getLastBiasUpdateVector()
.times(momentum).plus(
biasUpdateMatrixWithoutMomentum.times(1.0 - momentum));
Vector result = new Vector(biasUpdateMatrixWithMomentum
.getRowDimension());
for (int i = 0; i < biasUpdateMatrixWithMomentum.getRowDimension(); i++)
{
result.setValue(i, biasUpdateMatrixWithMomentum.get(i, 0));
}
layer.acceptNewBiasUpdate(result.copyVector());
return(result);
}
public void testSensitivityMatrixCalculationFromSucceedingLayer()
{
Matrix weightMatrix1 = new Matrix(2, 1);
weightMatrix1.set(0, 0, -0.27);
weightMatrix1.set(1, 0, -0.41);
Vector biasVector1 = new Vector(2);
biasVector1.setValue(0, -0.48);
biasVector1.setValue(1, -0.13);
Layer layer1 = new Layer(weightMatrix1, biasVector1,
new LogSigActivationFunction());
LayerSensitivity layer1Sensitivity = new LayerSensitivity(layer1);
Vector inputVector1 = new Vector(1);
inputVector1.setValue(0, 1);
layer1.feedForward(inputVector1);
Matrix weightMatrix2 = new Matrix(1, 2);
weightMatrix2.set(0, 0, 0.09);
weightMatrix2.set(0, 1, -0.17);
Vector biasVector2 = new Vector(1);
biasVector2.setValue(0, 0.48);
Layer layer2 = new Layer(weightMatrix2, biasVector2,
new PureLinearActivationFunction());
Vector inputVector2 = layer1.getLastActivationValues();
layer2.feedForward(inputVector2);
Vector errorVector = new Vector(1);
errorVector.setValue(0, 1.261);
LayerSensitivity layer2Sensitivity = new LayerSensitivity(layer2);
layer2Sensitivity.sensitivityMatrixFromErrorMatrix(errorVector);
layer1Sensitivity
.sensitivityMatrixFromSucceedingLayer(layer2Sensitivity);
Matrix sensitivityMatrix = layer1Sensitivity.getSensitivityMatrix();
Assert.AreEqual(2, sensitivityMatrix.getRowDimension());
Assert.AreEqual(1, sensitivityMatrix.getColumnDimension());
Assert.AreEqual(-0.0495, sensitivityMatrix.get(0, 0), 0.001);
Assert.AreEqual(0.0997, sensitivityMatrix.get(1, 0), 0.001);
}
public Vector calculateBiasUpdates(LayerSensitivity layerSensitivity,
double alpha, double momentum)
{
Layer layer = layerSensitivity.getLayer();
Matrix biasUpdateMatrixWithoutMomentum = layerSensitivity
.getSensitivityMatrix().times(alpha).times(-1.0);
Matrix biasUpdateMatrixWithMomentum = layer.getLastBiasUpdateVector()
.times(momentum).plus(
biasUpdateMatrixWithoutMomentum.times(1.0 - momentum));
Vector result = new Vector(biasUpdateMatrixWithMomentum
.getRowDimension());
for (int i = 0; i < biasUpdateMatrixWithMomentum.getRowDimension(); i++)
{
result.setValue(i, biasUpdateMatrixWithMomentum.get(i, 0));
}
layer.acceptNewBiasUpdate(result.copyVector());
return result;
}
public static Matrix calculateWeightUpdates(
LayerSensitivity layerSensitivity,
Vector previousLayerActivationOrInput, double alpha)
{
Layer layer = layerSensitivity.getLayer();
Matrix activationTranspose = previousLayerActivationOrInput.transpose();
Matrix weightUpdateMatrix = layerSensitivity.getSensitivityMatrix()
.times(activationTranspose).times(alpha).times(-1.0);
layer.acceptNewWeightUpdate(weightUpdateMatrix.copy());
return weightUpdateMatrix;
}
public static Vector calculateBiasUpdates(
LayerSensitivity layerSensitivity, double alpha)
{
Layer layer = layerSensitivity.getLayer();
Matrix biasUpdateMatrix = layerSensitivity.getSensitivityMatrix()
.times(alpha).times(-1.0);
Vector result = new Vector(biasUpdateMatrix.getRowDimension());
for (int i = 0; i < biasUpdateMatrix.getRowDimension(); i++)
{
result.setValue(i, biasUpdateMatrix.get(i, 0));
}
layer.acceptNewBiasUpdate(result.copyVector());
return result;
}
