Accord.Neuro.Learning.BackPropagationLearning.CalculateUpdates C# (CSharp) Method

        private void CalculateUpdates(double[] input)
        {
            // 1 - calculate updates for the first layer
            Layer layer = network.Layers[0];
            double[] errors = neuronErrors[0];
            double[][] layerWeightsUpdates = weightsUpdates[0];
            double[] layerThresholdUpdates = thresholdsUpdates[0];

            // cache for frequently used values
            double cachedMomentum = learningRate * momentum;
            double cached1mMomentum = learningRate * (1 - momentum);
            double cachedError;

            // for each neuron of the layer
            for (int i = 0; i < layer.Neurons.Length; i++)
            {
                cachedError = errors[i] * cached1mMomentum;
                double[] neuronWeightUpdates = layerWeightsUpdates[i];

                // for each weight of the neuron
                for (int j = 0; j < neuronWeightUpdates.Length; j++)
                {
                    // calculate weight update
                    neuronWeightUpdates[j] = cachedMomentum * neuronWeightUpdates[j] + cachedError * input[j];
                }

                // calculate threshold update
                layerThresholdUpdates[i] = cachedMomentum * layerThresholdUpdates[i] + cachedError;
            }

            // 2 - for all other layers
            for (int k = 1; k < network.Layers.Length; k++)
            {
                Layer layerPrev = network.Layers[k - 1];
                layer = network.Layers[k];
                errors = neuronErrors[k];
                layerWeightsUpdates = weightsUpdates[k];
                layerThresholdUpdates = thresholdsUpdates[k];

                // for each neuron of the layer
                for (int i = 0; i < layer.Neurons.Length; i++)
                {
                    cachedError = errors[i] * cached1mMomentum;
                    double[] neuronWeightUpdates = layerWeightsUpdates[i];

                    // for each synapse of the neuron
                    for (int j = 0; j < neuronWeightUpdates.Length; j++)
                    {
                        // calculate weight update
                        neuronWeightUpdates[j] = cachedMomentum * neuronWeightUpdates[j] + cachedError * layerPrev.Neurons[j].Output;
                    }

                    // calculate threshold update
                    layerThresholdUpdates[i] = cachedMomentum * layerThresholdUpdates[i] + cachedError;
                }
            }
        }