This custom Moving Average (MA) indicator is designed to help traders visualize price trends by smoothing out short-term market fluctuations. It acts as a visual guide on your trading chart, helping you identify the underlying direction of an asset's price movement.
Core Functionality
The script allows you to choose between four different types of moving averages. Depending on which method you select, the indicator calculates the "average" price differently to suit various trading styles:
- Simple Moving Average (SMA): This is the standard method. It takes the closing prices of a specific number of past periods and calculates the arithmetic mean. It treats all data points in the timeframe equally.
- Exponential Moving Average (EMA): This method gives more weight to recent price action. Because it reacts faster to new information than a simple average, it is often used by traders who want to capture trend changes more quickly.
- Smoothed Moving Average (SMMA): This version further "smooths" the data by using a formula that incorporates previous averages into the current calculation. It is designed to eliminate "noise" and provides a very steady, less reactive trend line.
- Linear Weighted Moving Average (LWMA): This method applies a linear weighting where the most recent price has the highest impact on the average, while older prices have progressively less impact. It balances the responsiveness of the EMA with a different mathematical progression.
Customization Options
The script includes several adjustable parameters that allow you to tailor the indicator to your specific strategy:
- MA_Period: You can define the "lookback" window (e.g., how many candles back the indicator should look). A higher number results in a smoother, slower line; a lower number makes it more sensitive to current price changes.
- MA_Shift: This allows you to move the resulting line forward or backward on the chart visually.
- MA_Method: This is the primary toggle used to switch between the four calculation types (SMA, EMA, SMMA, or LWMA) described above.
Technical Logic Summary
When the script runs, it automatically scans the historical closing prices of your chosen asset. It identifies the starting point based on your period settings and then performs the specific math required for your selected method. Once calculated, it draws a continuous line on your chart window, updating in real-time as new price data becomes available.
//+------------------------------------------------------------------+
//| Custom Moving Average.mq4 |
//| Copyright © 2004, MetaQuotes Software Corp. |
//| http://www.metaquotes.net/ |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2004, MetaQuotes Software Corp."
#property link "http://www.metaquotes.net/"
#property indicator_chart_window
#property indicator_buffers 1
#property indicator_color1 Red
//---- indicator parameters
extern int MA_Period=13;
int MA_Shift=0;
int MA_Method=1;
//---- indicator buffers
double ExtMapBuffer[];
//----
int ExtCountedBars=0;
//+------------------------------------------------------------------+
//| Custom indicator initialization function |
//+------------------------------------------------------------------+
int init()
{
int draw_begin;
string short_name;
//---- drawing settings
SetIndexStyle(0,DRAW_LINE);
SetIndexShift(0,MA_Shift);
IndicatorDigits(MarketInfo(Symbol(),MODE_DIGITS));
if(MA_Period<2) MA_Period=13;
draw_begin=MA_Period-1;
//---- indicator short name
switch(MA_Method)
{
case 1 : short_name="EMA("; draw_begin=0; break;
case 2 : short_name="SMMA("; break;
case 3 : short_name="LWMA("; break;
default :
MA_Method=0;
short_name="SMA(";
}
IndicatorShortName(short_name+MA_Period+")");
SetIndexDrawBegin(0,draw_begin);
//---- indicator buffers mapping
SetIndexBuffer(0,ExtMapBuffer);
//---- initialization done
return(0);
}
//+------------------------------------------------------------------+
//| |
//+------------------------------------------------------------------+
int start()
{
if(Bars<=MA_Period) return(0);
ExtCountedBars=IndicatorCounted();
//---- check for possible errors
if (ExtCountedBars<0) return(-1);
//---- last counted bar will be recounted
if (ExtCountedBars>0) ExtCountedBars--;
//----
switch(MA_Method)
{
case 0 : sma(); break;
case 1 : ema(); break;
case 2 : smma(); break;
case 3 : lwma();
}
//---- done
return(0);
}
//+------------------------------------------------------------------+
//| Simple Moving Average |
//+------------------------------------------------------------------+
void sma()
{
double sum=0;
int i,pos=Bars-ExtCountedBars-1;
//---- initial accumulation
if(pos<MA_Period) pos=MA_Period;
for(i=1;i<MA_Period;i++,pos--)
sum+=Close[pos];
//---- main calculation loop
while(pos>=0)
{
sum+=Close[pos];
ExtMapBuffer[pos]=sum/MA_Period;
sum-=Close[pos+MA_Period-1];
pos--;
}
//---- zero initial bars
if(ExtCountedBars<1)
for(i=1;i<MA_Period;i++) ExtMapBuffer[Bars-i]=0;
}
//+------------------------------------------------------------------+
//| Exponential Moving Average |
//+------------------------------------------------------------------+
void ema()
{
double pr=2.0/(MA_Period+1);
int pos=Bars-2;
if(ExtCountedBars>2) pos=Bars-ExtCountedBars-1;
//---- main calculation loop
while(pos>=0)
{
if(pos==Bars-2) ExtMapBuffer[pos+1]=Close[pos+1];
ExtMapBuffer[pos]=Close[pos]*pr+ExtMapBuffer[pos+1]*(1-pr);
pos--;
}
}
//+------------------------------------------------------------------+
//| Smoothed Moving Average |
//+------------------------------------------------------------------+
void smma()
{
double sum=0;
int i,k,pos=Bars-ExtCountedBars+1;
//---- main calculation loop
pos=Bars-MA_Period;
if(pos>Bars-ExtCountedBars) pos=Bars-ExtCountedBars;
while(pos>=0)
{
if(pos==Bars-MA_Period)
{
//---- initial accumulation
for(i=0,k=pos;i<MA_Period;i++,k++)
{
sum+=Close[k];
//---- zero initial bars
ExtMapBuffer[k]=0;
}
}
else sum=ExtMapBuffer[pos+1]*(MA_Period-1)+Close[pos];
ExtMapBuffer[pos]=sum/MA_Period;
pos--;
}
}
//+------------------------------------------------------------------+
//| Linear Weighted Moving Average |
//+------------------------------------------------------------------+
void lwma()
{
double sum=0.0,lsum=0.0;
double price;
int i,weight=0,pos=Bars-ExtCountedBars-1;
//---- initial accumulation
if(pos<MA_Period) pos=MA_Period;
for(i=1;i<=MA_Period;i++,pos--)
{
price=Close[pos];
sum+=price*i;
lsum+=price;
weight+=i;
}
//---- main calculation loop
pos++;
i=pos+MA_Period;
while(pos>=0)
{
ExtMapBuffer[pos]=sum/weight;
if(pos==0) break;
pos--;
i--;
price=Close[pos];
sum=sum-lsum+price*MA_Period;
lsum-=Close[i];
lsum+=price;
}
//---- zero initial bars
if(ExtCountedBars<1)
for(i=1;i<MA_Period;i++) ExtMapBuffer[Bars-i]=0;
}
//+------------------------------------------------------------------+
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