decaying fractions and make them closer












0












$begingroup$


My problem is actually algorithmic. I have two request queues, each holding its average wait time. For each queue I am holding x = total_wait_time, y = number_of_requests.



Let a = x/y the average of queue one
and b = w/z the average of queue two


Every second I would like to decay the queue so old request will have less effect on the average wait time. One simple way to achieve this will be:



Let $0 < C < 1$



$x' = C * x$



$y' = C * y$



this will keep the same average (C is reduced), but in the same time when a new update happens it will have more affect because it was not multiplied by 0.9 yet.



In addition I would like the averages to go towards each other. This is done in case no requests will enter one of the queues for a long time. To achieve this I can do the following every second:



a' = $frac{a + b} {2}$



Two achive both I thought about doing 90% of the first and 10% of the second:



$a' = frac{x'}{y'} = 0.9 * frac{C*x}{C*y} + 0.1 * frac{a + b}{2} = frac{...}{2*c*y}$



To reduce the history effect I need y' < y. this only happens when C < 0.5, but I do not want to rid the history so rapidly. What am I missing? Why doesn't it act as I expect? How can I fix the formula?



I hope it was understandable and thank you










share|cite|improve this question









$endgroup$

















    0












    $begingroup$


    My problem is actually algorithmic. I have two request queues, each holding its average wait time. For each queue I am holding x = total_wait_time, y = number_of_requests.



    Let a = x/y the average of queue one
    and b = w/z the average of queue two


    Every second I would like to decay the queue so old request will have less effect on the average wait time. One simple way to achieve this will be:



    Let $0 < C < 1$



    $x' = C * x$



    $y' = C * y$



    this will keep the same average (C is reduced), but in the same time when a new update happens it will have more affect because it was not multiplied by 0.9 yet.



    In addition I would like the averages to go towards each other. This is done in case no requests will enter one of the queues for a long time. To achieve this I can do the following every second:



    a' = $frac{a + b} {2}$



    Two achive both I thought about doing 90% of the first and 10% of the second:



    $a' = frac{x'}{y'} = 0.9 * frac{C*x}{C*y} + 0.1 * frac{a + b}{2} = frac{...}{2*c*y}$



    To reduce the history effect I need y' < y. this only happens when C < 0.5, but I do not want to rid the history so rapidly. What am I missing? Why doesn't it act as I expect? How can I fix the formula?



    I hope it was understandable and thank you










    share|cite|improve this question









    $endgroup$















      0












      0








      0





      $begingroup$


      My problem is actually algorithmic. I have two request queues, each holding its average wait time. For each queue I am holding x = total_wait_time, y = number_of_requests.



      Let a = x/y the average of queue one
      and b = w/z the average of queue two


      Every second I would like to decay the queue so old request will have less effect on the average wait time. One simple way to achieve this will be:



      Let $0 < C < 1$



      $x' = C * x$



      $y' = C * y$



      this will keep the same average (C is reduced), but in the same time when a new update happens it will have more affect because it was not multiplied by 0.9 yet.



      In addition I would like the averages to go towards each other. This is done in case no requests will enter one of the queues for a long time. To achieve this I can do the following every second:



      a' = $frac{a + b} {2}$



      Two achive both I thought about doing 90% of the first and 10% of the second:



      $a' = frac{x'}{y'} = 0.9 * frac{C*x}{C*y} + 0.1 * frac{a + b}{2} = frac{...}{2*c*y}$



      To reduce the history effect I need y' < y. this only happens when C < 0.5, but I do not want to rid the history so rapidly. What am I missing? Why doesn't it act as I expect? How can I fix the formula?



      I hope it was understandable and thank you










      share|cite|improve this question









      $endgroup$




      My problem is actually algorithmic. I have two request queues, each holding its average wait time. For each queue I am holding x = total_wait_time, y = number_of_requests.



      Let a = x/y the average of queue one
      and b = w/z the average of queue two


      Every second I would like to decay the queue so old request will have less effect on the average wait time. One simple way to achieve this will be:



      Let $0 < C < 1$



      $x' = C * x$



      $y' = C * y$



      this will keep the same average (C is reduced), but in the same time when a new update happens it will have more affect because it was not multiplied by 0.9 yet.



      In addition I would like the averages to go towards each other. This is done in case no requests will enter one of the queues for a long time. To achieve this I can do the following every second:



      a' = $frac{a + b} {2}$



      Two achive both I thought about doing 90% of the first and 10% of the second:



      $a' = frac{x'}{y'} = 0.9 * frac{C*x}{C*y} + 0.1 * frac{a + b}{2} = frac{...}{2*c*y}$



      To reduce the history effect I need y' < y. this only happens when C < 0.5, but I do not want to rid the history so rapidly. What am I missing? Why doesn't it act as I expect? How can I fix the formula?



      I hope it was understandable and thank you







      algebra-precalculus algorithms fractions






      share|cite|improve this question













      share|cite|improve this question











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      share|cite|improve this question










      asked Dec 11 '18 at 9:24









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