message: minor fix, hager zhang still broken
diff: @@ -211,7 +211,7 @@ where
  theta: 0.5,
  gamma: 0.66,
  eta: 0.01,
  - a_x_init: 0.0,
  + a_x_init: std::f64::EPSILON,
  a_x: std::f64::NAN,
  a_f: std::f64::NAN,
  a_g: std::f64::NAN,
  @@ -464,16 +464,12 @@ where
  }
  fn calc(&mut self, alpha: f64) -> Result<f64, Error> {
  - let tmp = self
  - .init_param
  - .scaled_add(alpha, &self.search_direction);
  + let tmp = self.init_param.scaled_add(alpha, &self.search_direction);
  self.apply(&tmp)
  }
  fn calc_grad(&mut self, alpha: f64) -> Result<f64, Error> {
  - let tmp = self
  - .init_param
  - .scaled_add(alpha, &self.search_direction);
  + let tmp = self.init_param.scaled_add(alpha, &self.search_direction);
  let grad = self.gradient(&tmp)?;
  Ok(self.search_direction.dot(&grad))
  }
  @@ -632,9 +628,7 @@ where
  // L2
  if bt_x - at_x > self.gamma * (self.b_x - self.a_x) {
  let c_x = (at_x + bt_x) / 2.0;
  - let tmp = self
  - .init_param
  - .scaled_add(c_x, &self.search_direction);
  + let tmp = self.init_param.scaled_add(c_x, &self.search_direction);
  let c_f = self.apply(&tmp)?;
  let grad = self.gradient(&tmp)?;
  let c_g = self.search_direction.dot(&grad);
  