I am trying to train an ANN but until now it is not learning the lower values of the training sample. I have tried using different python libraries to train ANN. The aim is to predict solar radiation from other weather parameters (regression problem). I think the ANN is confusing lower values (winter/cloudy days) with the night-time values (probably). I have tried the following but none of them worked;
1. Scaling data between different values e.g. [0,1],[-1,1]
2. Standardising data to have zero mean and unit variance
3. Shuffling the data
4. Increasing the training samples (from 3 years to 10 years)
5. Using different train functions
6. Trying different transfer functions
7. Using few input variables
8. Varying hidden layers and hidden layers' neurons