MT4 Indicator - Same arrow being displayed when they should vary

imamushroom 2015.08.30 09:49

Hi,

I'm learning to write indicators and I've a problem which I don't understand.

The indicator should display an green up or red down arrow depending on certain conditions but instead is displaying all red down arrows. The different conditions are being met as per the printed output but I don't understand why I'm not getting the desired results. I'm sure it's something simple.

Can you help?

Here's my code:

#property strict


#property indicator_chart_window

#property indicator_buffers 4

#property indicator_color1 Green

#property indicator_color2 Red

#property indicator_color3 DarkBlue

#property indicator_color4 Orange

#property indicator_width1 1

#property indicator_width2 1

#property indicator_width3 2

#property indicator_width3 2


extern int Fast_DEMA_period=4;

extern int Slow_DEMA_period=9;


//--- indicator buffer

double ExtUpArrowBuffer[];

double ExtDownArrowBuffer[];

double ExtDemaFast[];

double ExtDemaSlow[];

//+------------------------------------------------------------------+

//| Custom indicator initialization function                         |

//+------------------------------------------------------------------+

int OnInit(void)

  {

   string short_name;

   int    draw_begin=0;

//--- indicator short name

   short_name="BO_BuySell DEMA("+IntegerToString(Fast_DEMA_period)+") ("+IntegerToString(Slow_DEMA_period)+")";

   IndicatorShortName(short_name);

   IndicatorDigits(Digits);

   SetIndexStyle(0,DRAW_ARROW);

   SetIndexShift(0,0);

   SetIndexDrawBegin(0,draw_begin);

   SetIndexArrow(0,233);

   SetIndexBuffer(0,ExtUpArrowBuffer);

   SetIndexStyle(1,DRAW_ARROW);

   SetIndexShift(1,0);

   SetIndexDrawBegin(1,draw_begin);

   SetIndexArrow(1,234);

   SetIndexBuffer(1,ExtDownArrowBuffer);

   SetIndexStyle(2,DRAW_LINE);

   SetIndexShift(2,0);

   SetIndexDrawBegin(2,draw_begin);

   SetIndexBuffer(2,ExtDemaFast);

   SetIndexStyle(3,DRAW_LINE);

   SetIndexShift(3,0);

   SetIndexDrawBegin(3,draw_begin);

   SetIndexBuffer(3,ExtDemaSlow);

//--- initialization done

   return(INIT_SUCCEEDED);

  }

//+------------------------------------------------------------------+

//|  Moving Average                                                  |

//+------------------------------------------------------------------+

int OnCalculate(const int rates_total,

                const int prev_calculated,

                const datetime &time[],

                const double &open[],

                const double &high[],

                const double &low[],

                const double &close[],

                const long &tick_volume[],

                const long &volume[],

                const int &spread[])

  {

//--- check for bars count

   if(rates_total<0)

      return(0);

//--- counting from 0 to rates_total

   ArraySetAsSeries(ExtUpArrowBuffer,false);

   ArraySetAsSeries(ExtDownArrowBuffer,false);

   ArraySetAsSeries(close,false);

   ArraySetAsSeries(open,false);

//--- first calculation or number of bars was changed

   if(prev_calculated==0)

   {

      ArrayInitialize(ExtUpArrowBuffer,0);

      ArrayInitialize(ExtDownArrowBuffer,0);

   }

   int i,limit;

//--- first calculation or number of bars was changed

   if(prev_calculated==0)   

     {

      limit=4;

      //--- calculate first visible value

      double firstValue=2;

      for(i=0; i<limit; i++)

         firstValue+=close[i];

      firstValue/=4;

      ExtUpArrowBuffer[limit-1]=firstValue;

      ExtDownArrowBuffer[limit-1]=firstValue;

     }

   else

      limit=prev_calculated-1;

//--- main loop


   static double lastFastEMA, lastFastEMA_of_EMA;

   static double lastSlowEMA, lastSlowEMA_of_EMA;

   double fast_weight=2.0/(1.0+Fast_DEMA_period);

   double slow_weight=2.0/(1.0+Slow_DEMA_period);

   if(IndicatorCounted()==0)

     {

      ExtDemaFast[limit]  =Close[limit];

      lastFastEMA        =Close[limit];

      lastFastEMA_of_EMA  =Close[limit];

      ExtDemaSlow[limit]  =Close[limit];

      lastSlowEMA        =Close[limit];

      lastSlowEMA_of_EMA  =Close[limit];

      limit--;

     }


   for(i=limit; i<rates_total && !IsStopped(); i++)

   {

      lastFastEMA        =fast_weight*Close[i]   + (1.0-fast_weight)*lastFastEMA;

      lastFastEMA_of_EMA  =fast_weight*lastFastEMA   + (1.0-fast_weight)*lastFastEMA_of_EMA;

      ExtDemaFast[i]=2.0*lastFastEMA - lastFastEMA_of_EMA;

      lastSlowEMA        =slow_weight*Close[i]   + (1.0-slow_weight)*lastSlowEMA;

      lastSlowEMA_of_EMA  =slow_weight*lastSlowEMA   + (1.0-slow_weight)*lastSlowEMA_of_EMA;

      ExtDemaSlow[i]=2.0*lastSlowEMA - lastSlowEMA_of_EMA;


      bool up = ExtDemaFast[i] > ExtDemaSlow[i];

      bool down = ExtDemaFast[i] < ExtDemaSlow[i];

      

      int arrow = 233;

      color colour = clrGreen;

      double display_level = 0;


      Print("up = "+IntegerToString(up)+ " down = "+IntegerToString(down));               

      if( up && open[i] < ExtDemaSlow[i] )

      {

         display_level = open[i] - (1.5*_Point*10);

         Print("Up Slow "+DoubleToString(display_level));

         ExtUpArrowBuffer[i] = display_level;

         ExtDownArrowBuffer[i] = EMPTY_VALUE;

      }

      if( up && open[i] > ExtDemaFast[i] )

      {

         display_level = open[i] + (1.5*_Point*10);

         Print("Up Fast "+DoubleToString(display_level));

         ExtUpArrowBuffer[i] = EMPTY_VALUE;

         ExtDownArrowBuffer[i] = display_level;

      }

      if( down && open[i] > ExtDemaSlow[i] )

      {

         display_level = open[i] + (1.5*_Point*10);

         Print("Down Slow "+DoubleToString(display_level));

         ExtUpArrowBuffer[i] = EMPTY_VALUE;

         ExtDownArrowBuffer[i] = display_level;

      }

      if( down && open[i] < ExtDemaFast[i] )

      {

         display_level = open[i] - (1.5*_Point*10);

         Print("Down Fast "+DoubleToString(display_level));

         ExtUpArrowBuffer[i] = display_level;

         ExtDownArrowBuffer[i] = EMPTY_VALUE;

      }

   }

   

   double FastEMA        =fast_weight*Close[0]   + (1.0-fast_weight)*lastFastEMA,

   FastEMA_of_EMA  =fast_weight*FastEMA      + (1.0-fast_weight)*lastFastEMA_of_EMA;

   ExtDemaFast[0]=2.0*FastEMA - FastEMA_of_EMA;

   double SlowEMA        =slow_weight*Close[0]   + (1.0-slow_weight)*lastSlowEMA,

   SlowEMA_of_EMA  =slow_weight*SlowEMA      + (1.0-slow_weight)*lastSlowEMA_of_EMA;

   ExtDemaSlow[0]=2.0*SlowEMA - SlowEMA_of_EMA;

   

//--- return value of prev_calculated for next call

   return(rates_total);

  }