Directional Movement (ADX-DM)

ICE Data Services -

adx(), pdi(), ndi() Built-in Study Functions


Directional Movement (ADX-DM) indicates the strength of the overall trend. Typically, readings below 20-25 indicate a weak trend. +DI and -DI show the strength of the up trend (+DI) and the strength of the downtrend (-DI), respectively.


Syntax

adx( nLength , nSmoothing [, sym() | inv() ][, nBarIndex ] )
pdi( nLength , nSmoothing [, sym() | inv() ][, nBarIndex ] )
ndi ( nLength , nSmoothing [, sym() | inv() ][, nBarIndex ] )


Parameters

Parameter: Description: Default:
nLength Required. Number of periods to use for calculation. n/a
nSmoothing Required. Number of periods to use for calculation. n/a
sym() or
inv()
[Optional]  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.

These built-in study functions do not accept other series objects as the source for the study other than sym() or inv().

 

Code Examples

Single Line Indicator:
function main() {
  return new Array(adx(14, 14), pdi(14, 14), ndi(14, 14));
}

 

Single Line Study-on-Study Indicator:
N/A See notes.

 

Retrieve single values:

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

 

Initialize Series Objects:
//global Series Object variables
var xStudy1 = null;
var xStudy2 = null;
var xStudy3 = null;
function main() {
  if (xStudy1 == null) xStudy1 = adx(14, 14);
  if (xStudy2 == null) xStudy2 = pdi(14, 14);
  if (xStudy3 == null) xStudy3 = ndi(14, 14); // retrieve single values for conditional statements
  var nValue1_0 = xStudy1.getValue(0); // Current Bar Index value
  var nValue2_0 = xStudy2.getValue(0); // Current Bar Index value
  var nValue3_0 = xStudy3.getValue(0); // Current Bar Index value
  var nValue1_1 = xStudy1.getValue(-1); // Prior Bar Index value
  // Plot Current Bar Index Value
  return new Array(nValue1_0, nValue2_0, nValue3_0);
}

 

Initialize a Series Object based on an external interval:
// global Series Object variables
var xStudy1 = null;
var xStudy2 = null;
var xStudy3 = null;
var bInit = false; // Initialization flag
function main() {
  if (bInit == false) {
    xStudy1 = adx(14, 14, inv(20)); // 20-min interval
    xStudy2 = pdi(14, 14, inv(20)); // 20-min interval
    xStudy3 = ndi(14, 14, inv(20)); // 20-min interval
    bInit = true;
  } // retrieve single values for conditional statements
  var nValue1_0 = xStudy1.getValue(0); // Current Bar Index value
  var nValue1_1 = xStudy1.getValue(-1); // Prior Bar Index value
  // Synchronized Series plot
  return new Array(getSeries(xStudy1), getSeries(xStudy2), getSeries(xStudy3));
}

 

Initialize a Series Object based on an external symbol and interval:
// global Series Object variables
var xStudy1 = null;
var xStudy2 = null;
var xStudy3 = null;
var bInit = false; // Initialization flag
function main() {
  if (bInit == false) {
    xStudy1 = adx(14, 14, sym("IBM,20")); // IBM 20-min interval
    xStudy2 = pdi(14, 14, sym("IBM,20")); // IBM 20-min interval
    xStudy3 = ndi(14, 14, sym("IBM,20")); // IBM 20-min interval
    bInit = true;
  } // retrieve single values for conditional statements
  var nValue1_0 = xStudy1.getValue(0); // Current Bar Index value
  var nValue1_1 = xStudy1.getValue(-1); // Prior Bar Index value
  // Synchronized Series plot
  return new Array(getSeries(xStudy1), getSeries(xStudy2), getSeries(xStudy3));
}



See Also

Series Object
getSeries()
Built-in Study Functions
eSignal Forum Search Engine
Help Guides and Tutorials