is7n_trend_1

//+------------------------------------------------------------------+
//|                                                 iS7N_TREND_1.mq5 |
//|                                       Copyright 2010, SHOOTER777 |
//|                                                      s7n@mail.ru |
//+------------------------------------------------------------------+
#property copyright "Copyright 2010, SHOOTER777"
#property link      "s7n@mail.ru"
#property version   "1.00"
//---- indicator settings
#property indicator_chart_window
#property indicator_buffers 4
#property indicator_plots   1
//---- plot settings
#property indicator_label1  "iTREND_1"
#property indicator_type1   DRAW_LINE
#property indicator_color1  DarkBlue
#property indicator_style1  STYLE_SOLID
#property indicator_width1  2


//--- input parameters
input int Per = 14;
//--- 
int iMx = 300; // max bars to calculate
//--- indicator buffers
double dPlot [];
//---  handles buffers
double dBuf_1[];
double dBuf_2[];
//---  calculations buffers
double dBuf_3[];
double dBuf_4[];
//--- handles
int ihMA_1;
int ihMA_2;
//--- global variables
int P0,P2,P4;
int iIndCnt, iBufCnt, iRT, iPC;
int limit;
string sShNm;
double eee;
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int OnInit()
{
//---
int iPer   = StringConcatenate (sShNm,"iS7N_TREND_1( ",Per," )");
int iBars  = Bars(_Symbol,_Period);  // number of bars in the history
//---
SetIndexBuffer(0,dPlot,INDICATOR_DATA);
PlotIndexSetString(0,PLOT_LABEL,"TREND_1");
//---
SetIndexBuffer(1,dBuf_1,INDICATOR_CALCULATIONS);
//---
SetIndexBuffer(2,dBuf_2,INDICATOR_CALCULATIONS);
//---
SetIndexBuffer(3,dBuf_3,INDICATOR_CALCULATIONS);
//---
IndicatorSetInteger(INDICATOR_DIGITS,_Digits-1);
//---
IndicatorSetString(INDICATOR_SHORTNAME,sShNm);
//---  
vInPr(); 
//---
ihMA_1  = iMA(Symbol(), 0, P0 , 0, MODE_EMA, PRICE_CLOSE);
ihMA_2  = iMA(Symbol(), 0, P2 , 0, MODE_EMA, PRICE_CLOSE);
//---
return(0);
}
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int OnCalculate(const int rates_total,
                const int prev_calculated,
                const int begin,
                const double &price[])
{
if(prev_calculated<=0)
{
for(int i=0;i<=rates_total-1;i++)
{ 
dPlot [i]=EMPTY_VALUE;
dBuf_1[i]=EMPTY_VALUE;
dBuf_2[i]=EMPTY_VALUE;
dBuf_3[i]=EMPTY_VALUE;
}
}

//---

// the available bars should be greater than specified below
int iMn = 10*P0;
if(iMn>rates_total)return(0);
if(iMn>iMx) iMx=iMn ;
if(iMx>rates_total)iMx=rates_total;
//---    
int iii;
int limP0;
//---
int preMx = 1;
if(prev_calculated <= 0)// check for the first call
   {limit=rates_total-iMx;
    limP0 = limit+P0;}
else 
   {
   limit=prev_calculated-preMx;
   limP0 = limit;
   }

//---
iBufCnt  =  limit-1;
//---
ArrayResize(dBuf_4 ,P0);
//---
vInt ();
//---
for(int iii=limit;iii<=rates_total-1;iii++)
     { 
      dBuf_3[iii] = 2.0 * dBuf_2[iii] - dBuf_1[iii];
     }
     
for (iii = limP0; iii<=rates_total-1;iii++)
{
ArrayCopy(dBuf_4,dBuf_3,0,iii,P0);

dPlot[iii] = iMAOnArrayMQL4(dBuf_4, 0, P2, 0, 3, 0);
}

return(rates_total);
  }
//+------------------------------------------------------------------+
//+------------------------------------------------------------------+
//+------------------------------------------------------------------+
void vInPr()
{
P0=Per;
P2=Per/2;
P4= int (MathSqrt(Per));
}
void vInt()
{ int n1, n2;
n1=CopyBuffer(ihMA_1,0,0,iBufCnt+1,dBuf_1);
n2=CopyBuffer(ihMA_2,0,0,iBufCnt+1,dBuf_2);
}
//+------------------------------------------------------------------+
//+---------------------iMAOnArrayMQL4-------------------------------+
//+------------------------------------------------------------------+
double iMAOnArrayMQL4(double &array[],
                      int total,
                      int period,
                      int ma_shift,
                      int ma_method,
                      int shift)
  {
   double buf[],arr[];
   if(total==0) total=ArraySize(array);
   if(total>0 && total<=period) return(0);

   if(shift>total-period-ma_shift) return(0);

   switch(ma_method)
     {
      case MODE_SMA :
        {

         total=ArrayCopy(arr,array,0,shift+ma_shift,period);
         if(ArrayResize(buf,total)<0) return(0);
         double sum=0;
         int    i,pos=total-1;
         for(i=1;i<period;i++,pos--)
            sum+=arr[pos];
         while(pos>=0)
           {
            sum+=arr[pos];
            buf[pos]=sum/period;
            sum-=arr[pos+period-1];
            pos--;
           }
         return(buf[0]);
        }
      case MODE_EMA :
        {
        
         if(ArrayResize(buf,total)<0) return(0);
         double pr=2.0/(period+1);
         int    pos=total-2;
         while(pos>=0)
           {
            if(pos==total-2) buf[pos+1]=array[pos+1];
            buf[pos]=array[pos]*pr+buf[pos+1]*(1-pr);
            pos--;
           }
         return(buf[shift+ma_shift]);
        }
      case MODE_SMMA :
        {
         if(ArrayResize(buf,total)<0) return(0);
         double sum=0;
         int    i,k,pos;
         pos=total-period;
         while(pos>=0)
           {
            if(pos==total-period)
              {
               for(i=0,k=pos;i<period;i++,k++)
                 {
                  sum+=array[k];
                  buf[k]=0;
                 }
              }
            else sum=buf[pos+1]*(period-1)+array[pos];
            buf[pos]=sum/period;
            pos--;
           }
         return(buf[shift+ma_shift]);
        }
      case MODE_LWMA :
        {
         if(ArrayResize(buf,total)<0) return(0);
         double sum=0.0,lsum=0.0;
         double price;
         int    i,weight=0,pos=total-1;
         for(i=1;i<=period;i++,pos--)
           {
            price=array[pos];
            sum+=price*i;
            lsum+=price;
            weight+=i;
           }
         pos++;
         i=pos+period;
         while(pos>=0)
           {
            buf[pos]=sum/weight;
            if(pos==0) break;
            pos--;
            i--;
            price=array[pos];
            sum=sum-lsum+price*period;
            lsum-=array[i];
            lsum+=price;
           }//Print("total ",buf[shift+ma_shift]);
         return(buf[shift+ma_shift]);
        }
      default: return(0);
     }
   return(0);
  }