当我只需要关闭指标时，如何停止指标计算每个蜱？

Question

这是我从互联网上下载的指标，但我做了一些修改。我注意到指标计算了线性回归线以及每个刻度线上的上下波段。

我发现资源浪费，因为我只需要在每个条形图结束时计算行数;即，当条0结束并且形成新的条0时。

当条0仍然不完整时，它不应该计算任何东西。

我如何进行必要的更改？

谢谢！

//+------------------------------------------------------------------+
//|                                       Linear Regression Line.mq4 |
//|                                                      MQL Service |
//|                                           scripts@mqlservice.com |
//+------------------------------------------------------------------+
#property copyright "MQL Service"
#property link      "www.mqlservice.com"

#property indicator_chart_window
#property indicator_buffers   3

#property indicator_color1    White
#property indicator_width1    2

#property indicator_color2    Orange
#property indicator_width2    2

#property indicator_color3    Orange
#property indicator_width3    2

//---- input parameters
extern int LRLPeriod = 20;
extern int Number_SD = 2;

//---- buffers
double LRLBuffer[], LRLBuffer_Upper[], LRLBuffer_Lower[];

//int shift = 0;
int n = 0;
double sumx = 0;
double sumy = 0;
double sumxy = 0;
double sumx2 = 0;
double sumy2 = 0;
double yint = 0;
double r = 0;
double m = 0;

//+------------------------------------------------------------------+
//|                    INITIALIZATION FUNCTION                       |
//+------------------------------------------------------------------+
int init()
{
//---- indicators
SetIndexStyle(0, DRAW_LINE);
SetIndexBuffer(0, LRLBuffer);
SetIndexStyle(1, DRAW_LINE);
SetIndexBuffer(1, LRLBuffer_Upper);
SetIndexStyle(2, DRAW_LINE);
SetIndexBuffer(2, LRLBuffer_Lower);

IndicatorDigits(Digits);
if (LRLPeriod < 2) 
    LRLPeriod = 2;

IndicatorShortName("Linear Regression Line ("+LRLPeriod+")");
SetIndexDrawBegin(0, LRLPeriod+2);
IndicatorDigits(MarketInfo(Symbol(), MODE_DIGITS)+4);

return(0);
}

//+------------------------------------------------------------------+
//|                   DEINITIALIZATION FUNCTION                      |
//+------------------------------------------------------------------+
int deinit()
{
return(0);
}

//+------------------------------------------------------------------+
//|                      ITERATION FUNCTION                          |
//+------------------------------------------------------------------+
int start()
{
int limit, j, Counted_bars;
int counted_bars = IndicatorCounted();

if (counted_bars < 0) 
    counted_bars = 0;

if (counted_bars > 0) 
    counted_bars--;

limit = Bars - counted_bars;

for (int shift=limit-1; shift >= 0; shift--)
{
    sumx = 0;
    sumy = 0;
    sumxy = 0;
    sumx2 = 0;
    sumy2 = 0;
    for (n = 0; n <= LRLPeriod-1; n++)
    { 
        sumx = sumx + n;
        sumy = sumy + Close[shift + n];
        sumxy = sumxy + n * Close[shift + n];
        sumx2 = sumx2 + n * n;
        sumy2 = sumy2 + Close[shift + n] * Close[shift + n]; 
    }
    double temp = LRLPeriod * sumx2 - sumx * sumx;
    if (temp == 0)
        temp = .0000001;
//      m = (LRLPeriod * sumxy - sumx * sumy) / (LRLPeriod * sumx2 - sumx * sumx); 
    m = (LRLPeriod * sumxy - sumx * sumy) / temp; 

    temp = LRLPeriod;
    if (temp == 0)
        temp = .0000001;
    yint = (sumy + m * sumx) / temp; // was LRLPeriod (obviously)

    temp = MathSqrt((LRLPeriod * sumx2 - sumx * sumx) * (LRLPeriod * sumy2 - sumy * sumy));
    if (temp == 0)
        temp = .0000001;
    r = (LRLPeriod * sumxy - sumx * sumy) / temp;


    LRLBuffer[shift] = yint - m * LRLPeriod;

    //Print (" "+shift+" "+LRLBuffer[shift]);
}

//----------Added Upper and Lower Bands--------------//

   int    nBARs   = 0;  
   double LRLBuffer_CPY[];                        
   ArraySetAsSeries(LRLBuffer_CPY,True);                   

   j  = Bars - Counted_bars - 1;         
   while( j >  0 )                              
   {      
    ArrayCopy( LRLBuffer_CPY, LRLBuffer, 0, j, WHOLE_ARRAY );

    double StDev  = iStdDevOnArray( LRLBuffer_CPY, nBARs, LRLPeriod, 0, MODE_SMA, 0 );  

   LRLBuffer_Upper[j] = LRLBuffer[j] + (Number_SD * StDev);                                    
   LRLBuffer_Lower[j] = LRLBuffer[j] - (Number_SD * StDev);                                     

   j--;
  }



return(0);
}
//+------------------------------------------------------------------+

Answer 1

最简单的方法是使用标准OnCalculate(***)函数并仅运行主循环if(rates_total>prev_calculated)。

此外，在主周期中尝试for(int shift=limit-1;shift>0;shift--){（注意），顺便说一下，您确定需要shift=limit-1而不只是shift=limit吗？

Answer 2

新 - MQL4语法OnCalculate()无法帮助实现目标，而是使用此功能：

OnCalculate()语法可用，但代码块在启动时实际上仍然在您的控制之外，并且允许处理多少个渐进步骤。

解决方案是使用“旧”-syntax并添加“soft”-locking。

使用 static 变量有助于保持调用之间存储的临时值，并且只需将HOT-end重新计算从整个深度重新迭代，如果使用移位寄存器从刚冻结的[1]栏中更新。剩下的Bar [0]持续时间它.NOP / JIT / RET和你的代码并没有破坏单个独奏线程性能的脆弱性，共享（是！共享!!） ALL 自定义指标（在最近的新MQL4更新中真正的恶魔反模式......）：

int start(){
    static aCurrentTIME  = EMPTY;
    if (   aCurrentTIME == Time[0] ) return 0;   // .NOP/JIT/RET --^ 
           aCurrentTIME  = Time[0];              // .MOV/LOCK
 // -------------------------------------------- // .CALC:
    int limit = Bars - counted_bars;
    ...
    /* update just the "HOT"-end has just got into OHLCVT[1]-cells */
 // -------------------------------------------- // .FIN
}

Answer 3

根据具体情况，你也可以：

datetime calculatedBarTime;

void OnCalculate()
{
    if (  calculatedBarTime != Time[0] ) 
    {
          onBar();
    }
}

void onBar()
{
     calculatedBarTime  = Time[0];
  // on bar logic....
}