This script calculates and displays a technical indicator called the TRIX on a price chart. The TRIX aims to identify potential trend changes in the market. Here's how it works:
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Input: The user provides a key setting: the "EMA period." This number (e.g., 14) determines how many past price points are used to calculate the initial averages. A larger number makes the indicator smoother but also slower to react to price changes.
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Triple Smoothing: The core of the TRIX involves smoothing the price data three times using a technique called "Exponential Moving Average" (EMA). Think of an EMA like an average price that gives more weight to recent prices.
- First EMA: The script first calculates a regular EMA of the closing prices using the user-defined "EMA period."
- Second EMA: It then calculates an EMA of the first EMA values. This means it smooths the already-smoothed data.
- Third EMA: Finally, it calculates an EMA of the second EMA values. This results in a triple-smoothed version of the price data.
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Rate of Change: The TRIX then calculates the percentage change between the current triple-smoothed EMA value and the previous one. This percentage change is what's plotted on the chart.
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Output: The script displays the TRIX as a line on a separate window. The line goes up when the triple-smoothed EMA is increasing and goes down when it's decreasing. Traders often use the TRIX to identify potential overbought or oversold conditions, as well as possible trend reversals.
//+------------------------------------------------------------------+
//| TRIX.mq5 |
//| Copyright 2010, MetaQuotes Software Corp. |
//| http://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "2010, MetaQuotes Software Corp."
#property link "http://www.mql5.com"
#property description "Triple Exponential Average"
#include <MovingAverages.mqh>
//--- indicator settings
#property indicator_separate_window
#property indicator_buffers 4
#property indicator_plots 1
#property indicator_type1 DRAW_LINE
#property indicator_color1 Red
#property indicator_width1 1
#property indicator_label1 "TRIX"
#property indicator_applied_price PRICE_CLOSE
//--- input parameters
input int InpPeriodEMA=14; // EMA period
//--- indicator buffers
double TRIX_Buffer[];
double EMA[];
double SecondEMA[];
double ThirdEMA[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+
void OnInit()
{
//--- indicator buffers mapping
SetIndexBuffer(0,TRIX_Buffer,INDICATOR_DATA);
SetIndexBuffer(1,EMA,INDICATOR_CALCULATIONS);
SetIndexBuffer(2,SecondEMA,INDICATOR_CALCULATIONS);
SetIndexBuffer(3,ThirdEMA,INDICATOR_CALCULATIONS);
//--- sets first bar from what index will be drawn
PlotIndexSetInteger(0,PLOT_DRAW_BEGIN,3*InpPeriodEMA-3);
//--- name for index label
PlotIndexSetString(0,PLOT_LABEL,"TRIX("+string(InpPeriodEMA)+")");
//--- name for indicator label
IndicatorSetString(INDICATOR_SHORTNAME,"TRIX("+string(InpPeriodEMA)+")");
//--- indicator digits
IndicatorSetInteger(INDICATOR_DIGITS,5);
//--- initialization done
}
//+------------------------------------------------------------------+
//| Triple Exponential Average |
//+------------------------------------------------------------------+
int OnCalculate(const int rates_total,
const int prev_calculated,
const int begin,
const double &price[])
{
//--- check for data
if(rates_total<3*InpPeriodEMA-3)
return(0);
//---
int limit;
if(prev_calculated==0)
{
limit=3*(InpPeriodEMA-1);;
for(int i=0;i<limit;i++)
TRIX_Buffer[0]=EMPTY_VALUE;
}
else limit=prev_calculated-1;
//--- calculate EMA
ExponentialMAOnBuffer(rates_total,prev_calculated,0,InpPeriodEMA,price,EMA);
//--- calculate EMA on EMA array
ExponentialMAOnBuffer(rates_total,prev_calculated,InpPeriodEMA-1,InpPeriodEMA,EMA,SecondEMA);
//--- calculate EMA on EMA array on EMA array
ExponentialMAOnBuffer(rates_total,prev_calculated,2*InpPeriodEMA-2,InpPeriodEMA,SecondEMA,ThirdEMA);
//--- calculate TRIX
for(int i=limit;i<rates_total;i++)
{
if(ThirdEMA[i-1]!=0.0)
TRIX_Buffer[i]=(ThirdEMA[i]-ThirdEMA[i-1])/ThirdEMA[i-1];
else
TRIX_Buffer[i]=0.0;
}
//--- OnCalculate done. Return new prev_calculated.
return(rates_total);
}
//+------------------------------------------------------------------+
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