Ulcer Performance Index aka Martin Ratio - problems on refresh

[Scott Allen]

I've written an indicator for the Ulcer Performance Index, also known as the Martin Ratio. It works, but on chart refresh, it often doesn't recalculate and update the display correctly. I used code from the Ulcer Index to try to prevent constantly recalculating the whole thing, but it still has issues on a chart refresh. What am I missing?

//+------------------------------------------------------------------+
//|                                       UlcerPerformanceIndex.mq5  |
//|                                      Copyright 2024, Scott Allen |
//|                       https://www.mql5.com/en/users/mustaphamond |
//+------------------------------------------------------------------+
#property copyright "Copyright 2024, Scott Allen"
#property link      "https://www.mql5.com/en/users/mustaphamond"
#property version   "1.00"
#property indicator_separate_window
#property indicator_buffers 4
#property indicator_plots   1
#property indicator_label1  "UPI"
#property indicator_type1   DRAW_LINE
#property indicator_color1  clrDodgerBlue
#property indicator_style1  STYLE_SOLID
#property indicator_width1  2
input int      LookBackPeriod=262;
input int      SmoothPeriod = 10;
double         UPIBuffer[];
double         SmoothedUPIBuffer[];
double         UIBuffer[];
double         DrawDownBuffer[];

int OnInit()
  {
    if(LookBackPeriod <= SmoothPeriod)
    {
        Print("Error: LookBackPeriod must be greater than SmoothPeriod.");
        return(INIT_FAILED); // Initialization failed due to incorrect parameters
    }
    SetIndexBuffer(0, SmoothedUPIBuffer, INDICATOR_DATA);
    SetIndexBuffer(1, UPIBuffer, INDICATOR_DATA);
    SetIndexBuffer(2, UIBuffer, INDICATOR_CALCULATIONS);
    SetIndexBuffer(3, DrawDownBuffer, INDICATOR_CALCULATIONS);
   return(INIT_SUCCEEDED);
  }

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[])
  {
   int i=(int)MathMax(prev_calculated-1,1);  for(; i<rates_total && !_StopFlag; i++)
     {
      DrawDownBuffer[i]=((close[i]-close[ArrayMaximum(close,LookBackPeriod,i)])/close[ArrayMaximum(close,LookBackPeriod,i)]);
      double squaredDD = 0.0;
      double squaredAvg=0.0;
      if(i>=LookBackPeriod)
        {
            for(int x=i-LookBackPeriod;x<i;x++)
              {
               squaredDD=squaredDD+MathPow(DrawDownBuffer[x],2);
              }
            squaredAvg=squaredDD/LookBackPeriod;
            UIBuffer[i]=MathSqrt(squaredAvg);
            // Calculate Ulcer Performance Index
            double netProfit = (close[i] - close[i-LookBackPeriod]) / close[i-LookBackPeriod];
            UPIBuffer[i] = netProfit / UIBuffer[i];
            double sumUPI = 0.0;
            for(int j = i - SmoothPeriod + 1; j <= i; j++)
            {
               sumUPI += UPIBuffer[j];
            }
            SmoothedUPIBuffer[i] = sumUPI / SmoothPeriod;
         }
     }
   return(i);
  }

[William Roeder]

   int i=(int)MathMax(prev_calculated-1,1);  for(; i<rates_total && !_StopFlag; i++)

See How to do your lookbacks correctly #9 — #14 & #19. (2016)