Average True Range

ICE Data Services -

atr() Built-in Study Functions

The Average True Range study (ATR) is a measure of volatility. It was introduced by Welles Wilder in his book New Concepts in Technical Trading Systems and has since been used as a component of many indicators and trading systems. Wilder has found that the high ATR values often occur at market bottoms following a "panic" sell-off. Low ATR values are often found during extended sideways periods, such as those found at tops and after consolidation periods.

Syntax
atr( nLength [, sym() | inv() ][, nBarIndex ] )

Parameters
Parameter: Description: Default:
nLength Required. Number of periods to use for calculation.

 

n/a sym() or
inv()
[Optional]  Function of sym() or inv() to determine symbol/interval source for the study.

 

Chart's sym/inv nBarIndex [Optional]  Bar index of series to retrieve.

 

n/a


Return Value(s)

Returns a Series Object when nBarIndex is not specified.

Returns a single value when nBarIndex is specified.


Notes
Only available in versions 7.9 or later.

Code Examples
Single Line Indicator:
function main() {    return atr(14);}

Retrieve single values:
function main() {    var nValue_0 = atr(14, 0);  // Current Bar Index    var nValue_1 = atr(14, -1); // Prior Bar Index             return new Array(nValue_0, nValue_1);}

Initialize a Series Object:
var xStudy = null;function main() {    if (xStudy == null) {        xStudy = atr(14);    }            // retrieve single values for conditional statements    var nValue_0 = xStudy.getValue(0);  // Current Bar Index value    var nValue_1 = xStudy.getValue(-1); // Prior Bar Index value            return nValue_0;  // Plot Current Bar Index Value}

Initialize a Series Object based on an external interval:
var xStudy = null;var bInit = false;  // Initialization flagfunction main() {    if (bInit == false) {        xStudy = atr(14, inv(20));  // 20-min interval        bInit = true;    }            // retrieve single values for conditional statements    var nValue_0 = xStudy.getValue(0);  // Current Bar Index value    var nValue_1 = xStudy.getValue(-1); // Prior Bar Index value            return getSeries(xStudy);  // Synchronized Series plot}


Initialize a Series Object based on an external symbol and interval:
var xStudy = null;var bInit = false;  // Initialization flagfunction main() {    if (bInit == false) {        xStudy = atr(14, sym("IBM,20"));  // IBM 20-min interval        bInit = true;    }         // retrieve single values for conditional statements    var nValue_0 = xStudy.getValue(0);  // Current Bar Index value    var nValue_1 = xStudy.getValue(-1); // Prior Bar Index value         return getSeries(xStudy);  // Synchronized Series plot}


See Also
Series Object
getSeries()
Built-in Study Functions
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Tutorials