Problem 'Low' - constant variable cannot be passed as reference

[[Deleted]]

Hello,

I have find a good indicator, but it have a problem 'Low' - constant variable cannot be passed as reference

That is the global code :

//+------------------------------------------------------------------+
//|                                            sp market profile.mq4 |
//|                                      Copyright © 2008, sptrading | 
//+------------------------------------------------------------------+
#property copyright "sptrading"
#property indicator_chart_window

#include <mpxlib.mqh>

//+------------------------------------------------------------------+
//| mode: mode selection                                             |
//|     1: mp by day                                                 |
//|     2: mp by date from file                                      |
//| filename: datetime, comma separated;                             |
//|    (2008.12.28 11:00,2008.12.29 00:00)                           |
//|    if emtpy is assumed as <symbol>.mp                            |
//+------------------------------------------------------------------+

extern int mode = 1; 
extern string filename = "";
extern int days = 5;
extern double ticks = 10;
extern bool drawText = true;
extern bool drawBox = true;
extern bool drawPOC = true;
extern bool drawVolume = true;
extern bool std1Breakout = false;
extern bool unitBreakout = false;
extern bool AsiaSession = true;
extern bool EUSession = true;
extern bool USASession = true;

//+------------------------------------------------------------------+
//| Custor indicator deinitialization function                       |
//+------------------------------------------------------------------+
int deinit()
{
  mpxDrawErase();  
  return(0);
}
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
   string short_name;


//---- name for DataWindow and indicator subwindow label
   short_name="sp market profile";
   IndicatorShortName(short_name);
   SetIndexLabel(0,short_name);

   return(0);
  }

//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int start()
{  
  double onetick = 1/(MathPow(10,Digits))*ticks;  

  // Erase old one
  mpxDrawErase();  
  double pocsPrices[];
  double mpxVolume[];

   // Sessions  
  int sessions = 0;
  if (AsiaSession)
     sessions |= mpxeAsiaSession;
  if (EUSession)
     sessions |= mpxeEUSession;
  if (USASession)
     sessions |= mpxeUSASession;

  // MP  
  if (mode==1)
  {
   mpxMarketProfileByDay(pocsPrices, mpxVolume, Low, High, days, onetick, sessions, drawText, drawBox, drawPOC, drawVolume);
  }
  else if (mode==2)
  {
   if (filename == "")
      filename = mpxNameFromPeriod() + ".mp";
   mpxMarketProfileByFile(pocsPrices, mpxVolume, Low, High, filename, onetick, sessions, drawText, drawBox, drawPOC, drawVolume);
   }
   
   // Alert
   if (std1Breakout || unitBreakout)
      mpxSendMailAlert(pocsPrices, std1Breakout, unitBreakout);
//----
   return(0);
  }
//+------------------------------------------------------------------+

And the line where is the errors :

  mpxMarketProfileByDay(pocsPrices, mpxVolume, Low, High, days, onetick, sessions, drawText, drawBox, drawPOC, drawVolume);

and

 mpxMarketProfileByFile(pocsPrices, mpxVolume, Low, High, filename, onetick, sessions, drawText, drawBox, drawPOC, drawVolume)

If you can help me, it's good for me

Thanks

[William Roeder]

It errors there because your arguments are incompatible with the function definition. A definition which you do NOT show.	function(pocsPrices, mpxVolume, Low, High, ... TBD function(double& pocsPrices[], double& mpxVolume[], double& lows[], double& highs[], ...
Low[] and High[] are constant arrays. Always pass by constant reference unless you intend to modify the callers argument. You can't modify High[] or Low[]	function(pocsPrices, mpxVolume, Low, High, ... TBD function(double& prices[], double& volume[], const double& lows[], const double& highs[], ...

[[Deleted]]

Sorry's but I don't understand that you say

I havie to do what ?

THX

[Ex Ovo Omnia]

Your function declaration must explicitly contain const keyword when passing constants, the same way the OnCalculate function does, i.e.

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[]

[Stefano Antonio Piovesan]

Hi, I fixed it, now it builds with no errors.