code: public void setC(double C)
      {
          if(Double.isNaN(C) || Double.isInfinite(C) || C <= 0)
              throw new ArithmeticException("Aggressiveness must be a positive constant");
          this.C = C;
      }
docs: Set the aggressiveness parameter. Increasing the value of this parameter
  increases the aggressiveness of the algorithm. It must be a positive
  value. This parameter essentially performs a type of regularization on
  the updates
  <br>
  An infinitely large value is equivalent to being completely aggressive,
  and is performed when the mode is set to {@link Mode#PA}.
  
  @param C the positive aggressiveness parameter