A simulated dataset generated by P. Geurts for his 2002 PhD thesis
<em>Contributions to decision tree induction: bias/variance
tradeoff and time series classification.</em> from the University
of Liege.

class labels: 1: down-down (1306 cases) 2: up-down (1248 cases) 3:
down-up (1245 cases) 4: up-up (1201 cases)
