How to create a Target data ? Neural Network Tool

Question

Hello, I want to make a feedforward backpropagation neural network in order to solve a classification problem. Let's say I want to import a data set from UCI Machine Learning Repository ( this one ) which is 4x306. How do I create a Target data set in order to train it?

John Michell · Accepted Answer

The target for 2-class classification has dimensions [1 N] (N=306) with values {0,1}. However, if the ratio of N1/N0 is not in the interval [0.5, 2 ], then randomly add duplicates of the smaller class until the class sizes are equal. Occasionally, it helps to add a small noise component to the duplicates.
 
Use PATTERNNET with a LOGSIG activation function and TRAINSCG training function. The corresponding output, y = net(x), is a consistent estimate of the posterior probability of the "1" class, given the input x, i.e., P(classind = 1 | x ). the corresponding class index can be obtained from round(y).
 
In general, for c-class classification, the target matrix has dimensions [ c N ]with columns of the c-dimensional unit matrix. The row index of the 1 is the class index for that column. The assigned class is obtained from classind = vec2ind(y) (the row of the largest value).

How to create a Target data ? Neural Network Tool

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