Formula Basics

Five types of formulas exist:

•      QFormulas

•      Conditions

•      User Values

•      Custom Studies

•      Trade Systems

For our purposes, a formula can be either:

•      a mathematical calculation, e.g. addition or division to reach a numerical value;

•      a logical calculation, e.g. greater than or AND to reach a true/false value; or

•      a parameter (in the case of user values).

Formulas are applied to bars on charts and return either a value or an indication of a true condition.

Formula Components

Formulas are made up some combination of:

•      symbols

•      bar values

•      mathematical, relational, logical, and movement operators

•      offsets

•      functions

•      variables

•      parameters

•      comments

•      studies

•      other custom formulas

Consider these the building blocks of formulas.

Formulas are created on Formula Builder. Components can be typed manually, or you can use the toolbox to help build formulas.

Symbols

Formulas include either a specific symbol or the symbol placeholders (@).

Symbols must be entered in capital letters. Lowercase symbols display the inverse contract value. The system automatically defaults to all capital letters.

When the placeholder is used, the symbol is inherited from the application the formula is being used in.

For example:

This QFormula uses specific symbols: SPREAD(CLEM-2*CLEN+CLEQ,,,1:2:1)

This user value uses the placeholder: (High(@) + Low(@) + Close(@))/3

You can also use question marks:

In Formula Builder syntax preferences, symbols are included in the Identifier group.

Bar values

Comments

Bar values represent the outputs of chart types. For example:

•      Bar: Last

•      Bar: TrueRange

•      Bar: CurrentBestAsk

•      CVB: Open

•      Heikin-Ashi: Mid

•      Spread Bar: HLC3

•      TFlow: BestBidPrice

•      TFlow: DomBidVol1

Within formulas, bar values are formatted like this:

•      Last(@)[-1]

•      TrueRange(@)

•      CurrentBestAsk(@)

•      CVBXOpen(@,10)

•      HAMid(@)

•      SBHLC3(@,5X)

•      TFBestBidPrice(@,TFlowSimpleAggregation,1)

•      TFDomBidVol1(@,TFlowSimpleAggregation,1)

Bar parameters are also indicated. For example,  (@,TFlowSimpleAggregation,1). These parameters can be changed.

Bar values also include three studies: Bar, CVB, and TFlow External Data.

Note about Current Values: Current values (such as CurrentBestAsk, CurrentBestBid, and CurrentTickVol) were designed especially for building trade systems. As input variables in trade systems, the current bar values recalculate on every tick within the trade system regardless of recalculation settings (Setup > Chart Preferences > Recalc). Regular bar values follow the recalculation mode setting.

Bar values have no special syntax highlighting.

Operators

Operators create relationships between formula components. You can type operators in a formula, or you can insert them using the Toolbox.

In Formula Builder syntax preferences, mathematical and relational operators, commas, and question marks are included in the Operator group. Logical and movement operators are in the Keyword group.

Order of Operations

Mathematical (numerical value)

Relational (true/false)

Logical (true/false)

To illustrate these operators as clearly as possible, the variables A and B have been added.

You can type these operators in a formula, or you can use the Toolbox.

Movement (true/false)

You can type these operators in a formula, or you can use the Toolbox.

Offsets

Offsets identify which bar to apply the formula to.

An offset is indicated by using brackets [ ] around the offset value.

The offset value can be negative (for a bar in the past), positive (for a bar in the future), or zero (for the current bar). It is not necessary to indicate the current bar, as it is the default.

For example: High(@)[-2] = high of two bars ago

Functions

Functions represent the outputs of pre-defined functions. For example:

•      Bars Since

•      DOM Bid Volume

•      Maximum Since

•      Net Change

•      Spread

•      Standard Deviation

•      Yield

Within formulas, functions are formatted like this:

•      BarsSince(@,1,400)

•      DomBidVol(@,1,Single,1.0_secs)

•      MaxSince(@,none)

•      NC(@)

•      SPREAD(@)

•      STDDEV(@,8)

•      Yield(@)

Function parameters are also indicated. For example,  (@,1,Single,1.0_secs). These parameters can be changed.

Variables

A variable is a temporary value used to simplify complex, nested formulas.

A colon (:) is placed after the variable and a semi-colon (;) is placed at the end of the expression.

For example:

x:=MA(2, Sim, 7);

y:=close(@)[-5];

z:=x+y;

So, z = MA(2, Sim, 7) + close(@)[-5]

Variables do not apply across formulas, as user values do. So, x could mean three different things in three different formulas.

Parameters

Conditions, User Values, Custom Studies, and Trade System can include parameters.

For example: B.cqg.HVolLOw

In

HVOL(@,Percent,HVPeriod,AnnFactor) <  (1+Percent) * LoLevel (HVOL(@,Percent,HVPeriod,AnnFactor),Lookback,0)

HVPeriod, AnnFactor, Lookback, and Percent are parameters.

In Formula Builder syntax preferences, parameters are included in the Identifier group.

Comments

Comments are set off by /* and */.

There are two types of comments: those automatically generated by the system and those you add yourself.

For example, typing

SPREAD(

automatically generates

/* SPREAD(linear expression, [calculation mode], [tick size], [trade ratio], [BAT filter], [roll-over], [rounding mode])

Examples:

      SPREAD(42*HOE-CLE, L1, 0.01, 1:2, T:BA, 1)

      SPREAD(EP-ENQ, L1, 0.01, 1:1.33, T:BA, 1, MATH)

      SPREAD(EP/ENQ) */

SPREAD(@)

You can turn off auto-generated comments in Formula Builder preferences.

Studies

Studies represent the outputs of pre-defined studies. For example:

•      Moving Average

•      Moving Average Top Envelope

•      Momentum

•      Momentum Oversold

•      RSI Divergence Down

•      Filtered Bid Volume

Within formulas, studies are formatted like this:

•      MA(@,Sim,21)

•      MATE(@,Sim,21)

•      Mom(@,10)

•      Mom_OS(@,10)

•      RsDivDn(@,1,5,25,75,25,Sim,1,9)

•      VolFiltBid(@,0)

Study parameters are also indicated. For example,  (@,1,5,25,75,25,Sim,1,9). These parameters can be changed.

Other custom formulas

Formulas can be components of other formulas.

•      When you add a condition to a formula, prefix it with B, like this:

B.Condition(@)

•      When you add a user value to a formula, prefix it with V, like this:

V.UserValue(@)

•      When you add a study to a formula, format it like this:

STUDY.CURVE^(@)

CustomStudy.Average^(@)