finantic.Eval

finantic.Eval is a small but powerful extension that contains the Eval Indicator. This Indicator accepts an indicator expression of unlimited complexity and calculates the values for such a complex expression.

Indicator of Indicator

Imagine you need an indicator of an indicator like a doubly smoothed version of TR (True Range). You could code:

    TR tr = new TR(bars);
    EMA ema1 = new EMA(tr, 5);
    indi1 = new EMA(ema1, 5);

or with the Eval indicator:

    indi2 = new Eval(bars, "EMA(EMA(TR(bars), 5), 5)");

Transformations

Indicator Profiler and Indicator Selection both use transformations to make indicator values comparable among symbols and times.
These transformations can easily be calculated with the Eval indictor. In the lists below some example expressions are listed.

Indicator Profiler

IndicatorProfiler uses four transformations to make indicators comparable. Each transformation involves the use of an additional indicator.

• Below Signal Line
  Example expression: RSL(APTR(Bars,14),"EMA",5)
• Above Signal Line
  Example expression: RSL(APTR(Bars,14),"SMA",7)
• Conseq Down
  Example expression: ConsecUp(AEMA(Bars,15,15),10), 5, 10)
• Conseq up
  Example expression: ConsecUp(AEMA(Bars,15,15),10), 5, 10)

Indicator Selection

IndicatorSelection uses the following transformations.

• BandP - BandPosition: Prices relative to bands in percent
  Example expression: BandP(Close, ATRBandLower(Bars,Close,10,1.00), ATRBandUpper(Bars,Close,10,1.00))
• BWC - BandWidthChange: Rate of change of bandwidth
  Example expression: BWC(ATRBandLower(Bars,Close,10,1.00), ATRBandUpper(Bars,Close,10,1.00))
• CAtr - Relative to close ATR: Indicator relative to Close Prices in ATR
  Example expression: CAtr(Bars,AEMA(Bars,15,15),10)
• CPct - Releative to close percent: Indicator relative to close price in percent
  Example expression: CPct(Close,AEMA(Bars,15,15))
• CUD - Consecutive Up or Down Bars: Number of consecutive times input was up or down form N bars ago
  Example expression: CUD(APTR(Bars,14))
• PP - Price Proportional Indicator: Normalize a price proportional indicator by dividing it by a snoothed version of prices
  Example expression: PP(CyberCycle(Close,0.0175),Close,"EMA",100)
• ROC - Rate of Change
  Example expression: ROC(AEMA(Bars,15,15),1)
• RSL - Relative Signal Line
  Example expression: RSL(APTR(Bars,14),"EMA",5)
• PP+RSL
  Example expression: PP(RSL(ExpDev(Close,10,false),"EMA",5),Close,"EMA",100)

Background

finantic.Eval uses a tokenizer and a rules-based parser to parse indicator expressions with possibly nested indicators like "ROC(ATR(bars, 3), 7)" into a list of function calls that are executed when the Eval indicator is populated. Possible elements in such an indicator expression are (in order of precedence):

• Numbers
• strings
• Time Series: Open, High, Low, Close, Volume, etc.
• Indictors
• Parentheses
• Unary plus or minus
• Multiplication or Division
• Addition or Subtraction

Here is the complete Parsing Expression Grammar (PEG):

    IndiExpression => Sum as Indicator
    Sum => Product ( ('+' | '-') Product)*
    Product => SignedFactor (('*' | '/') SignedFactor)*
    SignedFactor => Factor | Sign Factor
    Sign => '+' | '-'
    Factor => Item | '(' Sum ')'
    Item => Indicator | [Identifier] | [Integer] | [Double]
    Indicator => [Identifier] '(' ArgumentList? ')'
    ArgumentList => Argument (',' Argument)*
    Argument =>  Sum | [String]