pub fn speed(&self) -> f32 {
        let (old_time, old_iter) = *self.time_history.front().unwrap();
        let (cur_time, cur_iter) = (Instant::now(), self.cur_step);
        (cur_iter - old_iter) as f32 / (cur_time - old_time).as_secs_f32()
    }
/// Compute the current average speed of iterations.
Compute the current average speed of iterations.
Compute the current average speed of iterations .
pub fn speed(&self) -> f32 {
        let (old_time, old_iter) = *self.time_history.front().unwrap();
        let (cur_time, cur_iter) = (Instant::now(), self.cur_step);
        (cur_iter - old_iter) as f32 / (cur_time - old_time).as_secs_f32()
    }
pub fn speed ( & self ) -> f32 { let ( old_time , old_iter ) = * self . time_history . front ( ) . unwrap ( ) ; let ( cur_time , cur_iter ) = ( Instant :: now ( ) , self . cur_step ) ; ( cur_iter - old_iter ) as f32 / ( cur_time - old_time ) . as_secs_f32 ( ) }
Compute the current average speed of iterations.
Compute the current average speed of iterations .
&self