Force Index
Created by Alexander Elder, the Force Index depicts volume-based buying and selling pressure based on the change in price. [Discuss] 💬
// C# usage syntax
IReadOnlyList<ForceIndexResult> results =
bars.ToForceIndex(lookbackPeriods);Parameters
| param | type | description |
|---|---|---|
lookbackPeriods | int | Lookback window (N) for the EMA of Force Index. Must be greater than 0 and is commonly 2 or 13 (shorter/longer view). Default is 2. |
Historical price bars requirements
You must have at least N+100 for 2×N periods of bars, whichever is more, to cover the warmup and convergence periods. Since this uses a smoothing technique for EMA, we recommend you use at least N+250 data points prior to the intended usage date for better precision.
bars is a collection of generic TBar historical price bars. It should have a consistent frequency (day, hour, minute, etc). See the Guide for more information.
Response
IReadOnlyList<ForceIndexResult>- This method returns a time series of all available indicator values for the
barsprovided. - It always returns the same number of elements as there are in the historical price bars.
- It does not return a single incremental indicator value.
- The first
Nperiods will benullsince they cannot be calculated.
🚩 ⚞ Convergence warning
The first N+100 periods will have decreasing magnitude, convergence-related precision errors that can be as high as ~5% deviation in indicator values for earlier periods.
ForceIndexResult
| property | type | description |
|---|---|---|
Timestamp | DateTime | Date from evaluated TBar |
ForceIndex | double | Force Index |
Utilities
See Utilities and helpers for more information.
Chaining
Results can be further processed on ForceIndex with additional chain-enabled indicators.
// example
var results = bars
.ToForceIndex(..)
.ToEma(..);This indicator must be generated from bars and cannot be generated from results of another chain-enabled indicator or method.
See Chaining indicators for more.
Streaming
Use the buffer-style List<T> when you need incremental calculations without a hub:
ForceIndexList forceIndexList = new(lookbackPeriods);
foreach (IBar bar in bars) // simulating stream
{
forceIndexList.Add(bar);
}
// based on `ICollection<ForceIndexResult>`
IReadOnlyList<ForceIndexResult> results = forceIndexList;Subscribe to a BarHub for advanced streaming scenarios:
BarHub barHub = new();
ForceIndexHub observer = barHub.ToForceIndexHub(lookbackPeriods);
foreach (IBar bar in bars) // simulating stream
{
barHub.Add(bar);
}
IReadOnlyList<ForceIndexResult> results = observer.Results;See Buffer lists and Stream hubs for full usage guides.