Question

以下MQL4脚本将MetaTrader中的数据导出到csv文件。不幸的是（至少对我而言），生成的csv文件中的数据顺序从0到1000,0是最新的（存在到过去）。我希望文件从1000到0（过去到现在）排序。

我将下面的写入数据循环更改为：for (int bar=Export_Bars; bar==0 bar--)，但这只是生成了一个空的csv文件。

#property script_show_inputs

input string    Export_FileName = "data\\data.csv"; 
input int       Export_Bars     = 20000; 
input int       StartHour = 10;
input int       EndHour = 19;

void OnStart()   
{
    int file = FileOpen(Export_FileName, FILE_WRITE|FILE_CSV|FILE_ANSI, ',');
    if (file != INVALID_HANDLE && (Hour() >= StartHour) && Hour() < EndHour)
    {
        // Write the header of data

        string row="";
        for (int i=0; i<=5; i++)
        {
            if (StringLen(row)) 
                row += ",";
            row += "Open"+i+",High"+i+",Low"+i+",Close"+i;
        }
        FileWrite(file, row);

        // Copy all required information from the history

        MqlRates rates[], rate;
        int count = Export_Bars + 5;
        if (CopyRates(Symbol(), Period(), 1, count, rates) < count)
        {
            Print("Error! Not enough history size for exporting required information.");
            return;
        }
        ArraySetAsSeries(rates, true);

        // Write data      

        for (int bar=0; bar<Export_Bars; bar++)
        {
            row="";
            double zlevel=0;
            for (int y=0; y<=5; y++)
            {
                if (StringLen(row)) 
                    row += ",";
                rate = rates[bar+y];
                if (y==0) 
                    zlevel = rate.open; // level of price calculation
                row += NormalizeDouble(rate.open -zlevel, Digits()) + ","
                       + NormalizeDouble(rate.high -zlevel, Digits()) + ","
                       + NormalizeDouble(rate.low  -zlevel, Digits()) + ","
                       + NormalizeDouble(rate.close-zlevel, Digits());
            }
            FileWrite(file, row);
        }

        FileClose(file);
        Print("Export of data is finished successfully.");
    } else Print("Error! Failed to create the file for data export. ", GetLastError());
}

所以我的问题是，为了将过去的数据导出到目前的顺序，需要对脚本进行哪些更改？

Answer 1

更改时间 - 反向 - 迭代器步进的循环构造函数：

 for ( int bar  = Export_Bars - 1;        // .LOOP-INIT(s)
           bar >= 0;                      // .LOOP-RUN-PRE-CONDITION
           bar--                          // .LOOP-RUN-POST-UPDATE(s)
       ) {...}                            // .LOOP-RUN-BODY

MT4导出脚本

1 个答案:

更改时间 - 反向 - 迭代器步进的循环构造函数：