Multilayer Perceptron (MLP) Training Algorithm
A Multilayer Perceptron (MLP) Training Algorithm is a feed-forward neural network training algorithm that can be implemented by a multi-layer feed-forward neural network training system to solve a multi-layer feed-forward neural network training task.
- Context:
- It is a supervised learning algorithm that is based on the backpropagation algorithm.
- It produces a Multilayer Feedforward Neural Network.
- Example(s)
- Counter-Example(s)
- See: Supervised Neural Network, Natural Language Processing, Feedforward Neural Network, Artificial Neural Network, Activation Function, Supervised Learning, Backpropagation, Perceptron, Linear Separability.
References
2017a
- (sklearn,2017) ⇒ http://scikit-learn.org/stable/modules/neural_networks_supervised.html#multi-layer-perceptron Retrieved:2017-12-3.
- QUOTE: Multi-layer Perceptron (MLP) is a supervised learning algorithm that learns a function [math]\displaystyle{ f(\cdot): R^m \rightarrow R^o }[/math] by training on a dataset, where [math]\displaystyle{ m }[/math] is the number of dimensions for input and [math]\displaystyle{ o }[/math] is the number of dimensions for output. Given a set of features [math]\displaystyle{ X = {x_1, x_2, \cdots, x_m} }[/math] and a target [math]\displaystyle{ y }[/math], it can learn a non-linear function approximator for either classification or regression. It is different from logistic regression, in that between the input and the output layer, there can be one or more non-linear layers, called hidden layers. Figure 1 shows a one hidden layer MLP with scalar output.
The leftmost layer, known as the input layer, consists of a set of neurons [math]\displaystyle{ \{x_i | x_1, x_2, \cdots, x_m\} }[/math] representing the input features. Each neuron in the hidden layer transforms the values from the previous layer with a weighted linear summation [math]\displaystyle{ w_1x_1 + w_2x_2 + \cdots + w_mx_m }[/math], followed by a non-linear activation function [math]\displaystyle{ g(\cdot):R \rightarrow R - }[/math] like the hyperbolic tan function. The output layer receives the values from the last hidden layer and transforms them into output values.
The module contains the public attributes
coefs_andintercepts_.coefs_is a list of weight matrices, where weight matrix at index [math]\displaystyle{ i }[/math] represents the weights between layer [math]\displaystyle{ i }[/math] and layer [math]\displaystyle{ i+1 }[/math].intercepts_is a list of bias vectors, where the vector at index [math]\displaystyle{ i }[/math] represents the bias values added to layer [math]\displaystyle{ i+1 }[/math].The advantages of Multi-layer Perceptron are:
- Capability to learn non-linear models.
- Capability to learn models in real-time (on-line learning) using
partial_fit.
- QUOTE: Multi-layer Perceptron (MLP) is a supervised learning algorithm that learns a function [math]\displaystyle{ f(\cdot): R^m \rightarrow R^o }[/math] by training on a dataset, where [math]\displaystyle{ m }[/math] is the number of dimensions for input and [math]\displaystyle{ o }[/math] is the number of dimensions for output. Given a set of features [math]\displaystyle{ X = {x_1, x_2, \cdots, x_m} }[/math] and a target [math]\displaystyle{ y }[/math], it can learn a non-linear function approximator for either classification or regression. It is different from logistic regression, in that between the input and the output layer, there can be one or more non-linear layers, called hidden layers. Figure 1 shows a one hidden layer MLP with scalar output.
- The disadvantages of Multi-layer Perceptron (MLP) include:
- MLP with hidden layers have a non-convex loss function where there exists more than one local minimum. Therefore different random weight initializations can lead to different validation accuracy.
- MLP requires tuning a number of hyperparameters such as the number of hidden neurons, layers, and iterations.
- MLP is sensitive to feature scaling.
- The disadvantages of Multi-layer Perceptron (MLP) include:
2017b
- (Wikipedia, 2017) ⇒ https://en.wikipedia.org/wiki/Multilayer_perceptron Retrieved:2017-12-3.
- A multilayer perceptron (MLP) is a class of feedforward artificial neural network. An MLP consists of at least three layers of nodes. Except for the input nodes, each node is a neuron that uses a nonlinear activation function. MLP utilizes a supervised learning technique called backpropagation for training. [1] [2] Its multiple layers and non-linear activation distinguish MLP from a linear perceptron. It can distinguish data that is not linearly separable.[3] Multilayer perceptrons are sometimes colloquially referred to as "vanilla" neural networks, especially when they have a single hidden layer. [4]
- ↑ Rosenblatt, Frank. x. Principles of Neurodynamics: Perceptrons and the Theory of Brain Mechanisms. Spartan Books, Washington DC, 1961
- ↑ Rumelhart, David E., Geoffrey E. Hinton, and R. J. Williams. "Learning Internal Representations by Error Propagation". David E. Rumelhart, James L. McClelland, and the PDP research group. (editors), Parallel distributed processing: Explorations in the microstructure of cognition, Volume 1: Foundation. MIT Press, 1986.
- ↑ Cybenko, G. 1989. Approximation by superpositions of a sigmoidal function Mathematics of Control, Signals, and Systems, 2(4), 303–314.
- ↑ Hastie, Trevor. Tibshirani, Robert. Friedman, Jerome. The Elements of Statistical Learning: Data Mining, Inference, and Prediction. Springer, New York, NY, 2009.
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