1

I am a beginner and I have developed code in Octave to train a neural network (as part of Andrew Ng's coursera course).

Now I would like to generate some datasets in Excel for simple mathematical functions and try and train my neural network implementation.

I tried y = x^2 and y = sin(x), **but my training accuracy is only around 67%.**

I have varied the number of hidden layer units, varied the lambda, but still don't get good results. Where could I be wrong?

Martin could you clarify why restricting your domain is necessary in training the network? – mburke05 – 2016-05-18T23:04:58.700

One the one hand you have to have a look at the range of values of the activation function of the last layer. Now you might simply take a linear output, but then the last weights might get enormous. Even small fluctuations at previous layers might so have a huge impact on the last one and this on the output – Martin Thoma – 2016-05-18T23:10:48.347