# Momentum

ICE Data Services -

mom() Built-in Study Functions

Momentum is calculated by subtracting a price for a given interval in the past from the current price. You determine how many intervals to go back for the price that is subtracted. The momentum study is an indication of overbuying or overselling. A positive value is an indication of overbuying , while a negative value indicates overselling.

Syntax
mom( nLength [, Series | sym() | inv() ][, nBarIndex ] )

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

n/a Series or
sym() or
inv()
[Optional]   Series Object or 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 mom(10);}`

Single Line Study-on-Study Indicator:
 `function main() { return mom(10, hl2() );}`

Retrieve single values:
 ``function main() { var nValue_0 = mom(10, 0); // Current Bar Index var nValue_1 = mom(10, -1); // Prior Bar Index return new Array(nValue_0, nValue_1);}``

Initialize a Series Object:
 ``var xStudy = null;function main() { if (xStudy == null) { xStudy = mom(10); } // 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 = mom(10, 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 = mom(10, 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}``