Contents

Introduction
Create Manual Indicators
Update Manual Indicators
Create Automatic Indicators
Get Indicator Values
Visualization

Indicator Reference

Parabolic Stop And Reverse

Introduction

Parabolic SAR Indicator Based on TA-Lib implementation

Create Manual Indicators

You can manually create a ParabolicStopAndReverse indicator, so it doesn’t automatically update. Manual indicators let you update their values with any data you choose. The following reference table describes the ParabolicStopAndReverse constructor.

ParabolicStopAndReverse()1/2

            ParabolicStopAndReverse QuantConnect.Indicators.ParabolicStopAndReverse (
     string    name,
     *decimal  afMax
   )

Create new Parabolic SAR.

ParabolicStopAndReverse()2/2

            ParabolicStopAndReverse QuantConnect.Indicators.ParabolicStopAndReverse (
     *decimal  afMax
   )

Create new Parabolic SAR.

Update Manual Indicators

You can update the indicator automatically or manually.

Automatic Update

To register a manual indicator for automatic updates with the security data, call the RegisterIndicator method.


private ParabolicStopAndReverse _psar;

// In Initialize()
_psar = new ParabolicStopAndReverse(name);
_psar.Updated += IndicatorUpdateMethod;

RegisterIndicator(symbol, _psar, Resolution.Daily);

// In IndicatorUpdateMethod()
if (_psar.IsReady)
{
    var indicatorValue = _psar.Current.Value;
}
    
# In Initialize()
self.psar = ParabolicStopAndReverse(name)
self.psar.Updated += self.IndicatorUpdateMethod

self.RegisterIndicator(symbol, self.psar, Resolution.Daily)

# In IndicatorUpdateMethod()
if self.psar.IsReady:
    indicator_value = self.psar.Current.Value

To customize the data that automatically updates the indicator, see Custom Indicator Periods and Custom Indicator Values.

Manual Update

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 Update method with a TradeBar, QuoteBar, or an IndicatorDataPoint. The indicator will only be ready after you prime it with enough data.

    
private ParabolicStopAndReverse _psar;
private Symbol symbol;

// In Initialize()
_psar = new ParabolicStopAndReverse();
symbol = AddEquity("SPY").Symbol;

// In OnData()
if (data.QuoteBars.ContainsKey(_symbol))
{
    _psar.Update(data.QuoteBars[symbol]);
}
if (_psar.IsReady)
{
    var indicatorValue = _psar.Current.Value;
}
    
# In Initialize()
self.psar = ParabolicStopAndReverse()
self.symbol = self.AddEquity("SPY").Symbol

# In OnData()
if data.QuoteBars.ContainsKey(self.symbol):
    self.psar.Update(data.QuoteBars[self.symbol])
if self.psar.IsReady:
    indicator_value = self.psar.Current.Value

Create Automatic Indicators

The PSAR method creates an ParabolicStopAndReverse indicator, sets up a consolidator to update the indicator, and then returns the indicator so you can use it in your algorithm.

The following reference table describes the PSAR method:

PSAR()1/1

            ParabolicStopAndReverse QuantConnect.Algorithm.QCAlgorithm.PSAR (
    Symbol                                symbol,
    *Decimal                              afStart,
    *Decimal                              afIncrement,
    *Decimal                              afMax,
    *Nullable<Resolution>           resolution,
    *Func<IBaseData, IBaseDataBar>  selector
   )

Creates a new Parabolic SAR indicator


If you don't provide a resolution, it defauls 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.

Get Indicator Values

To get the value of the indicator, use its Current.Value attribute.

private ParabolicStopAndReverse _psar;

// In Initialize()
var symbol = AddEquity("SPY").Symbol;
_psar = PSAR(symbol);

// In OnData()
if (_psar.IsReady)
{
    var current = _psar.Current.Value;
}
# In Initialize()
symbol = self.AddEquity("SPY").Symbol
self.psar = self.PSAR(symbol)

# In OnData()
if self.psar.IsReady:
    current = self.psar.Current.Value

Visualization

To plot indicator values, in the OnData event handler, call the Plot method.

private ParabolicStopAndReverse _psar;

// In Initialize()
var symbol = AddEquity("SPY").Symbol;
_psar = PSAR(symbol);

// In OnData()
if (_psar.IsReady)
{
    Plot("My Indicators", "parabolicstopandreverse", _psar.Current);
}
# In Initialize()
symbol = self.AddEquity("SPY").Symbol
self.psar = self.PSAR(symbol)

# In OnData()
if self.psar.IsReady:
    self.Plot("My Indicators", "parabolicstopandreverse", self.psar.Current)

For more information about plotting indicators, see Plotting Indicators.

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