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 weightUpdateMatrix2 = BackPropLearning.calculateWeightUpdates(
layer2Sensitivity, layer1.getLastActivationValues(), 0.1);
Assert.assertEquals(0.0809, weightUpdateMatrix2.get(0, 0), 0.001);
Assert.assertEquals(0.0928, weightUpdateMatrix2.get(0, 1), 0.001);
Matrix lastWeightUpdateMatrix2 = layer2.getLastWeightUpdateMatrix();
Assert.assertEquals(0.0809, lastWeightUpdateMatrix2.get(0, 0), 0.001);
Assert.assertEquals(0.0928, lastWeightUpdateMatrix2.get(0, 1), 0.001);
Matrix penultimateWeightUpdatematrix2 = layer2
.getPenultimateWeightUpdateMatrix();
Assert.assertEquals(0.0, penultimateWeightUpdatematrix2.get(0, 0),
0.001);
Assert.assertEquals(0.0, penultimateWeightUpdatematrix2.get(0, 1),
0.001);