CERDOnArray class is designed to calculate the Efficiency Ratio (ER) used in the Adaptive Moving Average (AMA) considering price movement direction. When the price is moving upwards the indicator has positive values, when it is moving downwards, - negative ones.

Usage:

Init() method with the following parameter is called in the OnInit() function:

• int aPeriod - efficiency ratio calculation period.

Solve() method with the following parameters is called in the OnCalculate() function:

• const int aRatesTotal is a rates_total variable from the OnCalculate() function parameters;
• const int aPrevCalc - prev_calculated variable from the OnCalculate() function;
• double aData[] - data buffer for the indicator calculation;
• double aERD[] - the buffer with the calculated value.

Additional methods:

• int BarsRequired() - returns the minimum number of bars for the indicator calculation;
• string Name() - returns the line with the indicator name.

Test_ERDOnArray.mq5 is a sample indicator showing CERDOnArray class application. IncERDOnArray file must be placed to MQL5\Include\IncOnArray of the terminal data folder (IncOnArray folder must be created).

Adaptive Moving Average (AMA) Technical Indicator is used for constructing a moving average with low sensitivity to price series noises and is characterized by the minimal lag for trend detection. This indicator was developed and described by Perry Kaufman in his book "Smarter Trading".