F. Network Modeling and Pruning Programs
  1. Given a trained MLP network;
   a. The pruning program measures the network' performance as a function of 
      the number of hidden units, and prunes the network of useless 
      hidden units. A network diagram is plotted, as is the mapping 
      error versus number of hidden units.
   b. The modelling program models the network with polynomials of 
      varying degree, allowing one to determine the effective degree 
      (the degree of a polynomial which models the network) or the 
      amount of nonlinearity of the network. Mapping error is plotted 
      versus network degree. First degree networks are virtually
      linear and do not require hidden units.
  2. The pruning program Prunes the net with a user-chosen amount of error and saves the 
      pruned net to disk
  3. Observe the parameter file with commented keyboard responses;

twod.tra            ! data file
weights.wts         ! weight file of trained network
tw.top              ! structure filename for the pruned network
tw.wts              ! weight filename for the pruned network
     
      The program will prune the network from the fast training program,
      which has weight file weights.wts,
      so that it has an MSE 1.14 times the original one.
      The program has created a new network, having 11 hidden units,
      which performs about as well as the original network.
      You can run this program on your own data.



