Supported Indicators
Wilder Swing Index
Introduction
This indicator calculates the Swing Index (SI) as defined by Welles Wilder in his book 'New Concepts in Technical Trading Systems'.
To view the implementation of this indicator, see the LEAN GitHub repository.
Using SI Indicator
To create an automatic indicators for WilderSwingIndex, call the SI helper method from the QCAlgorithm class. The SI method creates a WilderSwingIndex object, hooks it up for automatic updates, and returns it so you can used it in your algorithm. In most cases, you should call the helper method in the Initializeinitialize method.
public class WilderSwingIndexAlgorithm : QCAlgorithm
{
private Symbol _symbol;
private WilderSwingIndex _si;
public override void Initialize()
{
_symbol = AddEquity("SPY", Resolution.Daily).Symbol;
_si = SI(_symbol, 20);
}
public override void OnData(Slice data)
{
if (_si.IsReady)
{
// The current value of _si is represented by itself (_si)
// or _si.Current.Value
Plot("WilderSwingIndex", "si", _si);
}
}
} class WilderSwingIndexAlgorithm(QCAlgorithm):
def Initialize(self) -> None:
self._symbol = self.AddEquity("SPY", Resolution.Daily).Symbol
self.si = self.SI(self.symbol, 20)
def on_data(self, slice: Slice) -> None:
if self.si.IsReady:
# The current value of self.si is represented by self.si.Current.Value
self.plot("WilderSwingIndex", "si", self.si.Current.Value)
The following reference table describes the SI method:
SI()1/1
WilderSwingIndex QuantConnect.Algorithm.QCAlgorithm.SI (
Symbol symbol,
Decimal limitMove,
*Nullable<Resolution> resolution,
*Func<IBaseData, TradeBar> selector
)
Creates a Wilder Swing Index (SI) indicator for the symbol. The indicator will be automatically updated on the given resolution.
If you don't provide a resolution, it defaults to the security resolution. If you provide a resolution, it must be greater than or equal to the resolution of the security. For instance, if you subscribe to hourly data for a security, you should update its indicator with data that spans 1 hour or longer.
For more information about the selector argument, see Alternative Price Fields.
For more information about plotting indicators, see Plotting Indicators.
You can manually create a WilderSwingIndex indicator, so it doesn't automatically update. Manual indicators let you update their values with any data you choose.
Updating your indicator manually enables you to control when the indicator is updated and what data you use to update it. To manually update the indicator, call the Updateupdate method with a TradeBar. The indicator will only be ready after you prime it with enough data.
public class WilderSwingIndexAlgorithm : QCAlgorithm
{
private Symbol _symbol;
private WilderSwingIndex _si;
public override void Initialize()
{
_symbol = AddEquity("SPY", Resolution.Daily).Symbol;
_si = new WilderSwingIndex(20);
}
public override void OnData(Slice data)
{
if (data.Bars.TryGetValue(_symbol, out var bar))
{
_si.Update(bar);
}
if (_si.IsReady)
{
// The current value of _si is represented by itself (_si)
// or _si.Current.Value
Plot("WilderSwingIndex", "si", _si);
}
}
} class WilderSwingIndexAlgorithm(QCAlgorithm):
def Initialize(self) -> None:
self._symbol = self.AddEquity("SPY", Resolution.Daily).Symbol
self.si = WilderSwingIndex(20)
def on_data(self, slice: Slice) -> None:
bar = slice.Bars.get(self.symbol)
if bar:
self.si.Update(bar)
if self.si.IsReady:
# The current value of self.si is represented by self.si.Current.Value
self.plot("WilderSwingIndex", "si", self.si.Current.Value)
To register a manual indicator for automatic updates with the security data, call the RegisterIndicator method.
public class WilderSwingIndexAlgorithm : QCAlgorithm
{
private Symbol _symbol;
private WilderSwingIndex _si;
public override void Initialize()
{
_symbol = AddEquity("SPY", Resolution.Daily).Symbol;
_si = new WilderSwingIndex(20);
RegisterIndicator(_symbol, _si, Resolution.Daily);
}
public override void OnData(Slice data)
{
if (_si.IsReady)
{
// The current value of _si is represented by itself (_si)
// or _si.Current.Value
Plot("WilderSwingIndex", "si", _si);
}
}
} class WilderSwingIndexAlgorithm(QCAlgorithm):
def Initialize(self) -> None:
self._symbol = self.AddEquity("SPY", Resolution.Daily).Symbol
self.si = WilderSwingIndex(20)
self.RegisterIndicator(self.symbol, self.si, Resolution.Daily)
def on_data(self, slice: Slice) -> None:
if self.si.IsReady:
# The current value of self.si is represented by self.si.Current.Value
self.plot("WilderSwingIndex", "si", self.si.Current.Value)
The following reference table describes the WilderSwingIndex constructor:
WilderSwingIndex()1/2
WilderSwingIndex QuantConnect.Indicators.WilderSwingIndex (
string name,
decimal limitMove
)
Initializes a new instance of the WilderSwingIndex class using the specified name.
WilderSwingIndex()2/2
WilderSwingIndex QuantConnect.Indicators.WilderSwingIndex (
decimal limitMove
)
Initializes a new instance of the WilderSwingIndex class using the default name.
Visualization
The following image shows plot values of selected properties of WilderSwingIndex using the plotly library.
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