The backpropagation (BP) algorithm learns the classification model by training a multilayer feed-forward neural network. The generic architecture of the neural network for BP is shown in the following diagrams, with one input layer, some hidden layers, and one output layer. Each layer contains some units or perceptron. Each unit might be linked to others by weighted connections. The values of the weights are initialized before the training. The number of units in each layer, number of hidden layers, and the connections will be empirically defined at the very start.
The training tuples are assigned to the input layer; each unit in the input layer calculates the result with certain functions and the input attributes from the training tuple, and then the output is served as the input parameter for the hidden layer; the calculation here happened layer by layer. As a consequence, the output of the network contains all the output of each unit in...