Duty Cycle Calculation

David Smith

Below I want to calculate a ratio x:5, meaning for every Xminutes you are on, you are off or wait 5 mins to turn back on. On/Off is a complete cycle. Below are three cycles. I am trying to come up with a good way to do this using linq. Basically I am going to return how much time you have to wait or stay off before you start another cycle if that make sense.

So below you have a

ArrayOnOff[0]= "1:00AM On";
ArrayOnOff[1]= "1:01AM Off";
ArrayOnOff[2]= "1:02AM On";
ArrayOnOff[3]= "1:03AM Off";
ArrayOnOff[4]= "1:04AM On";
ArrayOnOff[5]= "1:05AM Off";

CycleId    StateOnOFF

     1            1:00AM        -on
     2            1:01AM        -off
     3            1:02AM        -on
     4            1:03AM        -off
     5            1:04AM        -on
     6            1:05AM        -off

8 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes13y ago
Accepted answer
To avoid using an explicit enumerator, I'd probably have done it like this:

Cycle[] cycles = new Cycle[ArrayOnOff.Length];
for(int i = 0; i < 6; i++) cycles[i] = GetCycleInfo(ArrayOnOff[i]);
double totalTimeUsed = 0;

for(int i = 1; i < cycles.Length; i++)
{
double diff = (cycles[i].TimeTag - cycles[i- 1].TimeTag).TotalSeconds;

if (i % 2 == 1)
totalTimeUsed += diff;
else
totalTimeUsed -= diff/5.0;

if (totalTimeUsed < 0) totalTimeUsed = 0;
}

totalTimeUsed -= (DateTime.Now - cycles[cycles.Length - 1].TimeTag).TotalSeconds / Ratio;

This isn't an ideal case for using LINQ but, if you must use it, then I'd try something like this:

double totalTimeUsed = 0;
Cycle prev = null;
ArrayOnOff.Select(aof => GetCycleInfo(aof)).Select((c, i) =>
{
if (i > 0)
{
double diff = (c.TimeTag - prev.TimeTag).TotalSeconds;

if (i % 2 == 1)
totalTimeUsed += diff;
else
totalTimeUsed -= diff/5.0;

if (totalTimeUsed < 0) totalTimeUsed = 0;
}
prev = c;
return 0.0; // need to return something although we don't use it
}).ToArray(); // add ToArray() to execute immediately

totalTimeUsed -= (DateTime.Now - prev.TimeTag).TotalSeconds / Ratio;
David Smith13y ago
Ok. Thanks.
Vulpes13y ago
'for' is faster than 'foreach' because the latter has more to do behind the scenes. However, the difference is not usually significant.

Here, I used 'for' because I needed the index of the element in the array to check whether it was odd or even and hence whether it was an 'off' or an 'on'.
David Smith13y ago
Which do you prefer to use in this case a foreach or for? Which is faster in your opinion. It seems the 'for' is faster?
Vulpes13y ago
Personally, I find using for or foreach easier to read than using enumerators explicitly.
David Smith13y ago
What's the reason for not using an explicit enumerator.
David Smith13y ago
I am going to try to explain this. If my ration is 1:5. That means for every minute that you are on, you have to stay off for five minutes, if that make since. I have an input file that will contain a sequence of on/off / on/ off with a timestamp.

The input file will populate the array below. The logic I want to simplify and come up with a better way of doing the logic below using linq if possible.

ArrayOnOff[0]= "1:00AM On";
ArrayOnOff[1]= "1:01AM Off";
ArrayOnOff[2]= "1:02AM On";
ArrayOnOff[3]= "1:03AM Off";
ArrayOnOff[4]= "1:04AM On";
ArrayOnOff[5]= "1:05AM Off";

Formula: The below formula calculates the amount of time you have left to stay on before exceeding the max. Everything needs to be in seconds

Max = 10min
Ratio = 5 (off/on)

TimeAvailable = Max - [OffTime - OnTime] + [DateTime.Now - OffTime] / Ratio

          IEnumerator enumerator = ArrayOnOff.GetEnumerator();
          enumerator.MoveNext();
          previousOn = GetCycleInfo((string)enumerator.Current);
          enumerator.MoveNext();
          previousOff = GetCycleInfo((string)enumerator.Current);

          double totalTimeUsed = (previousOff.TimeTag - previousOn.TimeTag).TotalSeconds;

          for (int i = 0; i < (ArrayOnOff.Count() / 2) - 1; ++i)
          {
              enumerator.MoveNext();
              Cycle newOn = GetCycleInfo((string)enumerator.Current);

              en.MoveNext();
              Cycle newOff = GetCycleInfo((string)enumerator.Current);

              double timeWaited = (newOn.TimeTag - previousOff.TimeTag).TotalSeconds;
              totalTimeUsed -= (newOn.TimeTag - previousOff.TimeTag).TotalSeconds / Ratio;

              // bought back all time?
              if (totalTimeUsed < 0.0)
              {
                  totalTimeUsed = 0.0;
              }

              previousOn = newOn;
              previousOff = newOff;

              totalTimeUsed += (previousOff.TimeTag - previousOn.TimeTag).TotalSeconds;
          }

          totalTimeUsed -= (DateTime.Now - previousOff.TimeTag).TotalSeconds / Ratio;
Kunal Vaishya13y ago
Hello,

Can you provide more details so i can help you.