public void drawFunctionToGraphic(Graphics2D g, int x, int y, int UNITYX, int UNITYY) {
    int _x, _y;

    g.setColor(Color.red);
    g.drawString("f(x) = " + F.toString(), 15, 20);

    g.setColor(Color.blue);
    for (double i = 0; ; i += EPSILON) {
      _x = (int) (i * UNITYX) + x / 2;
      _y = -(int) (F.evaluate(i) * UNITYY) + y / 2;

      g.drawLine(
          _x,
          _y,
          (int) ((i + EPSILON) * UNITYX) + x / 2,
          -(int) (F.evaluate(i + EPSILON) * UNITYY) + y / 2);

      if (_x < 0 || _x > x || _y < 0 || _y > y) break;
    }

    for (double i = 0; ; i -= EPSILON) {
      _x = (int) (i * UNITYX) + x / 2;
      _y = -(int) (F.evaluate(i) * UNITYY) + y / 2;

      g.drawLine(
          _x,
          _y,
          (int) ((i + EPSILON) * UNITYX) + x / 2,
          -(int) (F.evaluate(i + EPSILON) * UNITYY) + y / 2);

      if (_x < 0 || _x > x || _y < 0 || _y > y) break;
    }
  }
 public double evaluate_1(double value) {
   return F.evaluate_1(value);
 }