MATLAB: Neural Network training and improvement

neural network

My aim is to create neural network than will give threshold of distortions visibility after some actions with image. So, what I do, the inputa of net – DCT coefficients and targets maximal thresholds in which distortions aren't visible. I've prerared little collection of inputs-targets, and trying to train NN with help of feedforward function, but net don't want get trained? the graphics of training with differents number of neurons in hidden layer are here – http://www.dropbox.com/gallery/19618569/1/test2?h=849bb1
Help me, what is might be the problem, how to emprove my net? and also I cannot found how I can change the number of output neurons?

Best Answer

column2 = column1
column 4 = column3 = repmat([1 3 5 7]', N, 1)
Therefore you can make four plots of column5 vs column1 with column3 = constant.
If there is a deterministic trend to the four plots, the design should be straightforward provided your trn/val/tst partition results in three sets with similar dominant characteristics.
Before you design a net that corresponds to all of the column3 values, you might want to look at the four separate nets corresponding to column3 = constant.
Hope this helps.
Greg
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