code: public void setNu(double nu)
      {
          if(Double.isNaN(nu) || nu <= 0 || nu >= 1)
              throw new IllegalArgumentException("nu must be in the range (0, 1)");
          this.nu = nu;
      }
docs: The nu parameter for this SVM is not the same as the standard nu-SVM
  formulation, though it plays a similar role. It must be in the range
  (0, 1), where small values indicate a linearly separable problem (in the
  kernel space), and large values mean the problem is less separable. If
  the value is too small for the problem, the SVM may fail to converge or
  produce good results.
  
  @param nu the value between (0, 1)