Rx中包含历史和实时部分的流的度量标准
我的问题是Advanceable historical stream and live stream in Rx
的扩展我希望能够使用各种滚动时间范围（每小时，每天等）监控流中的更改。如果我的历史数据存在差距，例如在每小时的时间范围内，我的数据可以追溯到30＆＃39;以前和过去120＆＃39;以前，即我缺少[-120＆＃39;至-30＆＃39;]间隔，我想根据120＆＃39;观察。到目前为止我所拥有的代码的问题是，上面示例中的更改将基于值0，因为缺少-60观察值。
我不知道如何完成这项工作，或者是否有一个更清洁，更好的解决方案。
void Main()
{
const double bufferDuration = 8;
var now = DateTimeOffset.Now;
// create a historical log for testing
var log = new List<ValueTime>
{
new ValueTime { Ts = now.AddMilliseconds(-5000).ToString(), Balance = 1L },
new ValueTime { Ts = now.AddMilliseconds(-4000).ToString(), Balance = 2L },
new ValueTime { Ts = now.AddMilliseconds(-3000).ToString(), Balance = 4L }
};
var scheduler = new HistoricalScheduler();
scheduler.AdvanceTo(DateTime.Parse(log[0].Ts).AddSeconds(-0));
// historical part of the stream
var replay = Observable.Generate(
log.ToObservable().GetEnumerator(),
events => events.MoveNext(),
events => events,
events => events.Current.Balance,
events => DateTime.Parse(events.Current.Ts),
scheduler);
// create the real time part of the stream using a timer
var realTime = Observable.Create<long>(observer =>
{
var timer = Observable.Interval(TimeSpan.FromSeconds(2)).Select(x => 10 + x);
var disposable = timer.Subscribe(x => observer.OnNext(x));
return disposable;
});
// combine the two streams
var combined = replay
.Concat(realTime)
.Publish()
.RefCount();
combined.Timestamp(scheduler).Dump("Combined stream");
// use the real time stream to set the time of the historical scheduler's
realTime.Subscribe(_ =>
{
scheduler.AdvanceTo(DateTime.Now);
},
ex => Console.WriteLine(ex.Message),
() => Console.WriteLine("Done"));
// use a rolling buffer of "bufferDuration" length
var combinedBuffer = combined
.RollingBuffer(TimeSpan.FromSeconds(bufferDuration), scheduler)
.Select(x => x.Sum());
combinedBuffer.Timestamp(scheduler).Dump($"{bufferDuration}' Rolling buffer aggregation");
// display the values that are included in each window of the rolling buffer
combined
.RollingBuffer(TimeSpan.FromSeconds(bufferDuration), scheduler)
.Select(x => string.Join(",", x))
.Timestamp(scheduler).Dump($"{bufferDuration}' Rolling buffer lists");
// observe the difference between two consecutive observations
combinedBuffer.CombineWithPrevious((x, y) => y - x).Timestamp(scheduler).Dump($"{bufferDuration}' Rolling differences");
scheduler.Start();
}
class ValueTime
{
public long Balance;
public string Ts;
}
static class Extensions
{
public static IObservable<T[]> RollingBuffer<T>(
this IObservable<T> @this,
TimeSpan buffering, IScheduler scheduler)
{
return Observable.Create<
T[]>(o =>
{
var list = new LinkedList<Timestamped<T>>();
return @this.Timestamp(scheduler).Subscribe(tx =>
{
list.AddLast(tx);
while (list.First.Value.Timestamp < DateTime.Now.Subtract(buffering))
{
list.RemoveFirst();
}
o.OnNext(list.Select(tx2 => tx2.Value).ToArray());
}, o.OnError, o.OnCompleted);
});
}
public static IObservable<TResult> CombineWithPrevious<TSource, TResult>(this IObservable<TSource> source,
Func<TSource, TSource, TResult> resultSelector)
{
return source.Scan(
Tuple.Create(default(TSource), default(TSource)),
(previous, current) => Tuple.Create(previous.Item2, current))
.Select(t => resultSelector(t.Item1, t.Item2));
}
}
在LINQPad中运行它会产生以下结果：
在＆＃34; 8＆＃39;滚动差异＆＃34;表，上午1:13:30的条目应该是9而不是13，因为我希望在1:13:19 AM产生的4的值被包括在计算差异中。
似乎滚动缓冲区的当前版本或者我正在采取的方法是不够的，它可能会分散我正在努力实现的目标。我不能使用基于计数的缓冲区，因为如果我在观察中有漏洞，这可以让我很好地回到过去。如果我在下面的例子中使用2的计数，则10:00:00的滚动差异将使用x2 - x0，这不是我正在寻找的结果。
我正在寻找的行为是获得当前值和＆gt; = 8''之前（8''之前或8'之前）的滚动差异。例如。
Ts: 9:32:00 9:36:00 10:00:00 10:00:04 10:00:08 10:00:12 10:00:16
Level: --x0------x1-------x2-------x3-------x4-------x5-------x6---
Roll D.--x0----(x1-x0)-(x2-x1)--(x3-x1)--(x4-x2)--(x5-x3)--(x6-x4)-
1 个答案:
答案 0 :(得分：0)
我原本以为问题已经足够普遍，已经找到了解决方案，或者至少有一些人对此感兴趣。无论如何，在经历了相当多的时间之后，这主要是由于我对Rx的理解不足，我发现所需行为的步骤是使用上面的代码作为基础并且：
一个。修改滚动缓冲区扩展方法：
list.AddLast(tx);
while (list.First.Value.Timestamp < DateTime.Now.Subtract(buffering))
{
list.RemoveFirst();
}
o.OnNext(list.Select(tx2 => tx2.Value).ToArray());
为：
list.AddLast(tx);
var nowTime = scheduler.Now.DateTime;
System.Reactive.Timestamped<T> el = default(System.Reactive.Timestamped<T>);
while (list.Count > 1 && list.First.Value.Timestamp < nowTime.Subtract(buffering))
{
el = list.First.Value;
list.RemoveFirst();
}
if (el != default(System.Reactive.Timestamped<T>) && (list.Count <= 1 || list.First.Value.Timestamp > nowTime.Subtract(buffering)))
{
list.AddFirst(el);
}
o.OnNext(list.Select(tx2 => tx2.Value).ToArray());
B中。而不是值的总和列表，使用列表中最后一个元素和第一个元素之间的差异：
var combinedBuffer = combined
.RollingBuffer(TimeSpan.FromSeconds(bufferDuration), scheduler)
.Select(x => x.Last() - x.First());
℃。完全删除“CombineWithPrevious”调用。
combinedBuffer.CombineWithPrevious((x, y) => y - x).Timestamp(scheduler).Dump($"{bufferDuration}' Rolling differences");
带有一些调试打印输出的完整调用如下：
void Main()
{
const double bufferDuration = 8;
var now = DateTimeOffset.Now;
Console.WriteLine(now);
// create a historical log for testing
var log = new List<ValueTime>
{
new ValueTime { Ts = now.AddMilliseconds(-5000).ToString(), Balance = 1L },
new ValueTime { Ts = now.AddMilliseconds(-4000).ToString(), Balance = 2L },
new ValueTime { Ts = now.AddMilliseconds(-3000).ToString(), Balance = 4L }
};
var scheduler = new HistoricalScheduler();
scheduler.AdvanceTo(DateTime.Parse(log[0].Ts));
// historical part of the stream
var replay = Observable.Generate(
log.ToObservable().GetEnumerator(),
events => events.MoveNext(),
events => events,
events => events.Current.Balance,
events => DateTime.Parse(events.Current.Ts),
scheduler);
// create the real time part of the stream using a timer
var realTime = Observable.Create<long>(observer =>
{
var timer = Observable.Interval(TimeSpan.FromSeconds(2)).Select(x => 10 + x);
var disposable = timer.Subscribe(x => observer.OnNext(x));
return disposable;
});
// combine the two streams
var combined = replay
.Concat(realTime)
.Publish()
.RefCount();
combined.Timestamp(scheduler).Dump("Combined stream");
// use the real time stream to set the time of the historical scheduler's
realTime.Subscribe(_ =>
{
scheduler.AdvanceTo(DateTime.Now);
},
ex => Console.WriteLine(ex.Message),
() => Console.WriteLine("Done"));
var combinedRollingBuffer = combined
.RollingBufferDeltaChange(TimeSpan.FromSeconds(bufferDuration), scheduler)
.Publish()
.RefCount();
// use a rolling buffer of "bufferDuration" length
var combinedBuffer = combinedRollingBuffer
//.Select(x => x.Sum());
.Select(x => x.Last() - x.First());
combinedBuffer.Timestamp(scheduler).Dump($"{bufferDuration}'' Rolling buffer aggregation");
// display the values that are included in each window of the rolling buffer
combinedRollingBuffer
.Select(x => string.Join(",", x))
.Timestamp(scheduler).Dump($"{bufferDuration}'' Rolling buffer lists");
scheduler.Start();
}
class ValueTime
{
public long Balance;
public string Ts;
}
static class Extensions
{
public static IObservable<T[]> RollingBufferDeltaChange<T>(
this IObservable<T> @this,
TimeSpan buffering, IScheduler scheduler)
{
return Observable.Create<
T[]>(o =>
{
var list = new LinkedList<Timestamped<T>>();
return @this.Timestamp(scheduler).Subscribe(tx =>
{
list.AddLast(tx);
Console.WriteLine($"{scheduler.Now} Adding Tx: {tx.Timestamp} {tx.Value} list.First: {list.First.Value.Timestamp} {list.First.Value.Value} list.Last: {list.Last.Value.Timestamp} {list.Last.Value.Value}");
DateTime nowTime = scheduler.Now.DateTime; // DateTime.Now;
System.Reactive.Timestamped<T> el = default(System.Reactive.Timestamped<T>);
while (list.Count > 1 && list.First.Value.Timestamp < nowTime.Subtract(buffering))
{
el = list.First.Value;
list.RemoveFirst();
Console.WriteLine($"{scheduler.Now} Removing el: {el.Timestamp} {el.Value} {list.Count}");
}
if (el != default(System.Reactive.Timestamped<T>) && (list.Count <= 1 || list.First.Value.Timestamp > nowTime.Subtract(buffering)))
{
list.AddFirst(el);
Console.WriteLine($"{scheduler.Now} Adding el: {el.Timestamp} {el.Value} {list.Count}");
if (list.Count > 0)
{
Console.WriteLine($"{scheduler.Now} el: {el.Timestamp} {el.Value} list.First: {list.First.Value.Timestamp} {list.First.Value.Value} list.Last: {list.Last.Value.Timestamp} {list.Last.Value.Value}");
}
}
o.OnNext(list.Select(tx2 => tx2.Value).ToArray());
}, o.OnError, o.OnCompleted);
});
}
}
它产生了我正在寻找的行为：
如果除了Advanceable historical stream and live stream in Rx中我最初提到詹姆斯世界的答案之外，我还不会在reactive extensions sliding time window中承认他的回应和他的答案，这将是一个很大的遗漏。没有他们的帮助，不仅在这些特定的帖子中，而且在其他许多帖子中，我都没有机会在我的代码中使用Rx，所以非常感谢他们两个。
相关问题
最新问题
- 我写了这段代码，但我无法理解我的错误
- 我无法从一个代码实例的列表中删除 None 值，但我可以在另一个实例中。为什么它适用于一个细分市场而不适用于另一个细分市场？
- 是否有可能使 loadstring 不可能等于打印？卢阿
- java中的random.expovariate()
- Appscript 通过会议在 Google 日历中发送电子邮件和创建活动
- 为什么我的 Onclick 箭头功能在 React 中不起作用？
- 在此代码中是否有使用“this”的替代方法？
- 在 SQL Server 和 PostgreSQL 上查询，我如何从第一个表获得第二个表的可视化
- 每千个数字得到
- 更新了城市边界 KML 文件的来源？