//+------------------------------------------------------------------+ //| Fractal_Bands.mq4 | //| Copyright © 2008, jppoton@yahoo.com | //| http://fractalfinance.blogspot.com/ | //+------------------------------------------------------------------+ #property copyright "Copyright © 2008, jppoton@yahoo.com" #property link "http://fractalfinance.blogspot.com/" #property indicator_chart_window #property indicator_buffers 3 #property indicator_color1 Red #property indicator_width1 2 #property indicator_color2 Red #property indicator_width2 1 #property indicator_color3 Red #property indicator_width3 1 //************************************************************ // Input parameters //************************************************************ extern int e_period =30; extern int normal_speed =30; extern double alpha =2.0; extern int shift =0; extern int e_type_data =PRICE_CLOSE; //************************************************************ // Constant //************************************************************ string INDICATOR_NAME="Fractals Bands"; string FILENAME ="Fractal_bands.mq4"; double LOG_2; //************************************************************ // Private vars //************************************************************ double ExtOutputBuffer[]; double UpperBuffer[]; double LowerBuffer[]; int g_period_minus_1; //+-----------------------------------------------------------------------+ //| FUNCTION : init | //| Initialization function | //| Check the user input parameters and convert them in appropriate types.| //+-----------------------------------------------------------------------+ int init() { // Check e_period input parameter if(e_period < 2 ) { Alert( "[ 10-ERROR " + FILENAME + " ] input parameter \"e_period\" must be >= 1 (" + e_period + ")" ); return( -1 ); } if(e_type_data < PRICE_CLOSE || e_type_data > PRICE_WEIGHTED ) { Alert( "[ 20-ERROR " + FILENAME + " ] input parameter \"e_type_data\" unknown (" + e_type_data + ")" ); return( -1 ); } IndicatorBuffers(3); SetIndexBuffer(0,ExtOutputBuffer); SetIndexStyle(0,DRAW_LINE,STYLE_SOLID,2); SetIndexBuffer(1,UpperBuffer); SetIndexStyle(1,DRAW_LINE); SetIndexBuffer(2,LowerBuffer); SetIndexStyle(2,DRAW_LINE); SetIndexDrawBegin(0,2*e_period); SetIndexDrawBegin(1,2*e_period); SetIndexDrawBegin(2,2*e_period); g_period_minus_1=e_period - 1; LOG_2=MathLog( 2.0 ); //---- return( 0 ); } //+------------------------------------------------------------------+ //| FUNCTION : deinit | //| Custor indicator deinitialization function | //+------------------------------------------------------------------+ int deinit() { return(0); } //+------------------------------------------------------------------+ //| FUNCTION : start | //| This callback is fired by metatrader for each tick | //+------------------------------------------------------------------+ int start() { int counted_bars=IndicatorCounted(); if(counted_bars < 0) return(-1); if(counted_bars>0) counted_bars--; int limit=Bars-counted_bars; if(counted_bars==0) limit-=1+MathMax(e_period,g_period_minus_1); _computeLastNbBars(limit); //---- return( 0 ); } //+================================================================================================================+ //+=== FUNCTION : _computeLastNbBars ===+ //+=== ===+ //+=== ===+ //+=== This callback is fired by metatrader for each tick ===+ //+=== ===+ //+=== In : ===+ //+=== - lastBars : these "n" last bars must be repainted ===+ //+=== ===+ //+================================================================================================================+ //+------------------------------------------------------------------+ //| FUNCTION : _computeLastNbBars | //| This callback is fired by metatrader for each tick | //| In : - lastBars : these "n" last bars must be repainted | //+------------------------------------------------------------------+ double tmpArray[]; void _computeLastNbBars( int lastBars ) { switch( e_type_data ) { case PRICE_CLOSE : ArrayCopy(tmpArray,Close,0,0,WHOLE_ARRAY); FRACTAL_BANDS(lastBars, tmpArray); break; case PRICE_OPEN : ArrayCopy(tmpArray,Open,0,0,WHOLE_ARRAY); FRACTAL_BANDS(lastBars, tmpArray); break; case PRICE_HIGH : ArrayCopy(tmpArray,High,0,0,WHOLE_ARRAY); FRACTAL_BANDS(lastBars, tmpArray); break; case PRICE_LOW : ArrayCopy(tmpArray,Low,0,0,WHOLE_ARRAY); FRACTAL_BANDS(lastBars, tmpArray); break; default : Alert( "[ 20-ERROR " + FILENAME + " ] the imput parameter e_type_data <" + e_type_data + "> is unknown" ); } } //+------------------------------------------------------------------+ //| FUNCTION : FRACTAL_BANDS | //| Compute the Fractal Bands for input data | //| In : | //| - lastBars : these "n" last bars are considered for | //| calculating the fractal dimension | //| - inputData : data array on which the computation is applied | //| For further theoretical explanations, see my blog: | //| http://fractalfinance.blogspot.com/ | //+------------------------------------------------------------------+ void FRACTAL_BANDS( int lastBars, double &inputData[] ) { int pos, iteration; double diff, priorDiff; double length; double priceMax, priceMin; double fdi,trail_dim,beta,sum,newres,deviation,frasma,hurst; int speed,k; //---- for( pos=lastBars; pos>=0; pos-- ) { priceMax=_highest( e_period, pos, inputData ); priceMin=_lowest( e_period, pos, inputData ); length =0.0; priorDiff=0.0; //---- for( iteration=0; iteration <= g_period_minus_1; iteration++ ) { if(( priceMax - priceMin)> 0.0 ) { diff =(inputData[pos + iteration] - priceMin )/( priceMax - priceMin ); if(iteration > 0 ) { length+=MathSqrt( MathPow( diff - priorDiff, 2.0)+(1.0/MathPow( e_period, 2.0)) ); } priorDiff=diff; } } if(length > 0.0 ) { fdi=1.0 +(MathLog( length)+ LOG_2 )/MathLog( 2 * g_period_minus_1 ); } else { /* ** The FDI algorithm suggests in this case a zero value. ** I prefer to use the previous FDI value. */ fdi=0.0; } hurst=2-fdi; // The Hurst exponent trail_dim=1/hurst; // This is the trail dimension, the inverse of the Hurst-Holder exponent beta=trail_dim/2; speed=MathRound(normal_speed*beta); ExtOutputBuffer[pos-shift]=iMA(NULL,0,speed,0,0,0,pos); // Buffer of the FRASMA sum=0.0; k=pos+g_period_minus_1; frasma=ExtOutputBuffer[pos-shift]; while(k>=pos) { newres=Close[k]-frasma; sum+=newres*newres; k--; } deviation=2*MathSqrt(sum/e_period); // 2 standard deviations around the frasma UpperBuffer[pos-shift]=frasma+deviation*MathPow(alpha,hurst); LowerBuffer[pos-shift]=frasma-deviation*MathPow(alpha,hurst); } } //+------------------------------------------------------------------+ //| FUNCTION : _highest | //| Search for the highest value in an array data | //| In : | //| - n : find the highest on these n data | //| - pos : begin to search for from this index | //| - inputData : data array on which the searching for is done | //| | //| Return : the highest value | | //+------------------------------------------------------------------+ double _highest( int n, int pos, double &inputData[] ) { int length=pos + n; double highest=0.0; //---- for( int i=pos; i < length; i++ ) { if(inputData[i] > highest)highest=inputData[i]; } return( highest ); } //+------------------------------------------------------------------+ //| FUNCTION : _lowest | ===+ //| Search for the lowest value in an array data | //| In : | //| - n : find the hihest on these n data | //| - pos : begin to search for from this index | //| - inputData : data array on which the searching for is done | //| | //| Return : the highest value | //+------------------------------------------------------------------+ double _lowest( int n, int pos, double &inputData[] ) { int length=pos + n; double lowest=9999999999.0; //---- for( int i=pos; i < length; i++ ) { if(inputData[i] < lowest)lowest=inputData[i]; } return( lowest ); } //+------------------------------------------------------------------+