WebCab Technical Analysis Web Services for Delphi v1.1

DirectionalMovementIndicator Class

Implements the Directional Movement Indicator (MDI) and Average Directional Indicator (ADX) which was first developed by Wellas Wilder in order to classify price moves and trends.

For a list of all members of this type, see DirectionalMovementIndicator Members.

System.Object
   DirectionalMovementIndicator

public class DirectionalMovementIndicator

Remarks

These ideas where first made public within Wilder's first book "New Concepts in Technical Trading Systems" (Dec 1978).

The techniques described here where originally developed in the process of developing a trading system and can still be used in this way. Today these methods are most commonly used to evaluate the strength of a price move or trend. Care should be taken with the direct application of this approach since it was first developed and applied to markets with exhibited lower volatility than todays markets.

The central idea of this approach is to compare the range of price of two subsequent periods and from this information infer the overall direction of the market. In order to ensure the stability of the indicators a moving average is often used in conjunction with the basic indicators. For further details please see the PDF documentation.

One Period and Multi Period Versions

For many of the indicators we provide essentially two versions of the same method. The first version evaluates the indicator over the entire period given and the second version evaluates the indicator over all the sub-periods of a given length. Moreover, the version which evaluates over all sub-periods of a given length will return the results as an array where the 1st term of the array will be the value associated with the most recent sub-period, and the previous element corresponding to the previous sub-period and so on.

The naming of these two versions will follow the convention that if the indicator which evaluates over the entire period and returns a single element is named ABCIndicator, then the corresponding indicator over all sub-periods (of a given length) which returns an array will be denoted by ABCIndicatorOverPeriod.

For example, if our source data has N elements then the two versions of a given indicator, where the number of periods used within the sub-periods is n would correspond to:

  1. ABCIndicator - Evaluation of the indicator over the whole period of length N.
  2. ABCIndicatorOverPeriod - Will return an array where the first term is the value of the indicator ABCIndicator on the most recent n periods, and the next term is the value of the indicator ABCIndicator on the previous n+1 periods minus the most recent period and so on. That is, for each iterative evaluation 'the window of evaluation' is shifted one place back.

Requirements

Namespace: Indicators

Assembly: WebCab.DelphiWebServices.TA (in WebCab.DelphiWebServices.TA.dll)

See Also

DirectionalMovementIndicator Members | Indicators Namespace