There are 2^4 = 16 rules in the generated FIS
matrix and the number of fitting parameters is
108, including 24 nonlinear parameters and 80
linear parameters. This is a proper balance
between number of fitting parameters and number
of training data (500). Ten epochs of training
take about 4 min. on a SUN SPARC II workstation.
The ANFIS command looks like this:

>> [fismat1, error] = anfis(trn_data, fismat, [], [], chk_data);

To save time, we will load the training results
directly.