private void read_problem() throws IOException {
BufferedReader fp = new BufferedReader(new FileReader(input_file_name));
Vector<Double> vy = new Vector<Double>();
Vector<svm_node[]> vx = new Vector<svm_node[]>();
int max_index = 0;
while (true) {
String line = fp.readLine();
if (line == null) break;
StringTokenizer st = new StringTokenizer(line, " \t\n\r\f:");
vy.addElement(atof(st.nextToken()));
int m = st.countTokens() / 2;
svm_node[] x = new svm_node[m];
for (int j = 0; j < m; j++) {
x[j] = new svm_node();
x[j].index = atoi(st.nextToken());
x[j].value = atof(st.nextToken());
}
if (m > 0) max_index = Math.max(max_index, x[m - 1].index);
vx.addElement(x);
}
prob = new svm_problem();
prob.l = vy.size();
prob.x = new svm_node[prob.l][];
for (int i = 0; i < prob.l; i++) prob.x[i] = vx.elementAt(i);
prob.y = new double[prob.l];
for (int i = 0; i < prob.l; i++) prob.y[i] = vy.elementAt(i);
if (param.gamma == 0 && max_index > 0) param.gamma = 1.0 / max_index;
fp.close();
}
public void eval(
final EvolutionState state,
final int thread,
final GPData input,
final ADFStack stack,
final GPIndividual individual,
final Problem problem) {
RegressionData rd = ((RegressionData) (input));
children[0].eval(state, thread, input, stack, individual, problem);
rd.x = Math.tan(rd.x);
}