示例#1
0
    private static void solve_nu_svr(svm_problem prob, svm_parameter param,
                                     double[] alpha, Solver.SolutionInfo si) {
      int l = prob.l;
      double C = param.C;
      double[] alpha2 = new double[2 * l];
      double[] linear_term = new double[2 * l];
      short[] y = new short[2 * l];
      int i;

      double sum = C * param.nu * l / 2;
      for (i = 0; i < l; i++) {
        alpha2[i] = alpha2[i + l] = Math.Min(sum, C);
        sum -= alpha2[i];

        linear_term[i] = -prob.y[i];
        y[i] = 1;

        linear_term[i + l] = prob.y[i];
        y[i + l] = -1;
      }

      Solver_NU s = new Solver_NU();
      s.Solve(2 * l, new SVR_Q(prob, param), linear_term, y,
              alpha2, C, C, param.eps, si, param.shrinking);

      svm.info("epsilon = " + (-si.r) + Environment.NewLine);

      for (i = 0; i < l; i++)
        alpha[i] = alpha2[i] - alpha2[i + l];
    }
示例#2
0
    private static void solve_nu_svc(svm_problem prob, svm_parameter param,
                                     double[] alpha, Solver.SolutionInfo si) {
      int i;
      int l = prob.l;
      double nu = param.nu;

      short[] y = new short[l];

      for (i = 0; i < l; i++)
        if (prob.y[i] > 0)
          y[i] = +1;
        else
          y[i] = -1;

      double sum_pos = nu * l / 2;
      double sum_neg = nu * l / 2;

      for (i = 0; i < l; i++)
        if (y[i] == +1) {
          alpha[i] = Math.Min(1.0, sum_pos);
          sum_pos -= alpha[i];
        } else {
          alpha[i] = Math.Min(1.0, sum_neg);
          sum_neg -= alpha[i];
        }

      double[] zeros = new double[l];

      for (i = 0; i < l; i++)
        zeros[i] = 0;

      Solver_NU s = new Solver_NU();
      s.Solve(l, new SVC_Q(prob, param, y), zeros, y,
              alpha, 1.0, 1.0, param.eps, si, param.shrinking);
      double r = si.r;

      svm.info("C = " + 1 / r + Environment.NewLine);

      for (i = 0; i < l; i++)
        alpha[i] *= y[i] / r;

      si.rho /= r;
      si.obj /= (r * r);
      si.upper_bound_p = 1 / r;
      si.upper_bound_n = 1 / r;
    }