Arrays with the double& declaration, how to make them global?

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Greatings MQL4 coders and a happy new year!,

My current AE has a function like this:

double FunctionName(double& Array1[], double& Array2[], double& Array3[])

Because of the use of that ampersand char (needed because their values are changed within this function) it seems impossible to declare these types a global (please correct me when I'm wrong). As a result of this  I'm forced to use the ArrayResize() function within this function. This is not only inefficient (this function is called many times and has 16 arrays) but also makes my function too inflexible for my purpose.

Is there a way to declare arrays global and that I can resize them only once within the Init() function? 

Thank you in advance for any feedback,

 Jim 

 
Because of the use of that ampersand char (needed because their values are changed within this function) it seems impossible to declare these types a global (please correct me when I'm wrong.)
Your wrong;
//+------------------------------------------------------------------+
//| Ema's                                                            |
//+------------------------------------------------------------------+
double  ema.fast[], ema.slow[]; // Exported to STD, STC
                    int emaBarsFast;    double  emaAlphaFast;
void OnInitEmaFastRB(){ emaBarsFast=0;          emaAlphaFast=2.0/(EMA.Fast+1); }
                    int emaBarsSlow;    double  emaAlphaSlow;
void OnInitEmaSlowRB(){ emaBarsSlow=0;          emaAlphaSlow=2.0/(EMA.Slow+1); }
void OnTickEmaFastRB(){
    CalcEMA(Close.RB, emaAlphaFast, emaBarsFast, ema.fast); }
void OnTickEmaSlowRB(){
    CalcEMA(Close.RB, emaAlphaSlow, emaBarsSlow, ema.slow); }
void CalcEMA(double signal[], double alpha, int& barsDone, double& buffer[]){
    double  barsToDo = ArraySize(signal);
    if (!ResizeBuffer(buffer, BarsToDo))    return;
    if (barsDone == 0){
        int shift = barsToDo - 1;       double  sigPrev = signal[shift];    }
    else{   shift = barsToDo - barsDone;        sigPrev = buffer[shift+1];  }
    for(; shift >= 0; shift--){
        sigPrev += alpha * (signal[shift] - sigPrev);   buffer[shift]=sigPrev; }
    barsDone = barsToDo;
    return;
}
bool ResizeBuffer(double buffer[], int size){
    if (ArraySize(buffer) != size){
        ArraySetAsSeries(buffer, false);    // Shift values B[2]=B[1]; B[1]=B[0]
        if (ArrayResize(buffer, size) <= 0){
            trading.disabled = "ArrayResize failed: "+GetLastError();
            return(false);  }
        ArraySetAsSeries(buffer, true);
    }
    return(true);
}
 
WHRoeder:
Your wrong;

Nice example, thanks for sharing! 
So by adjusting that buffer[] array in a separate function (ResizeBuffer), you're allowed to change it type from double& to double ?

Jim 

 
double& just means the function is allowed to change the values. It's not changing its type
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