How to detect when a trend line crosses the MA curve

Question

The trend line crosses the moving average curve (Yellow) at the violet point indicating a Buy signal. I wanted to know if there was a way to programmatically detect the crossing of a trend line with the moving average curve to place a Buy or Sell signal.

I know how to draw the trend line but I don't know how to read the values that interest me on this trend line. Any idea would be welcome.

Daniel Kniaz Daniel Kniaz · Accepted Answer · 2020-04-26T11:08:01

First, get time&data of the points of the trend line (here: they are in struct). Next, find the slope. Finally, you can compute the trend line value at any point of time. In the sample example below, all is moved into struct. Keep in mind, that if you have several such lines on the chart, you have to loop over all of them to find the last one (if you need the last, of course).

struct TrendLine{
   datetime m_startDt;
   double   m_start;
   datetime m_endDt;
   double   m_end;
   double   m_slope; // slope, price per bar

   void     Init(const string objName) {
      m_startDt=(datetime)ObjectGetInteger(0,objName,OBJPROP_TIME1);
      m_start  = ObjectGetDouble(0,objName,OBJPROP_PRICE1);
      m_endDt  =(datetime)ObjectGetInteger(0,objName,OBJPROP_TIME2);
      m_end    = ObjectGetDouble(0,objName,OBJPROP_PRICE2);
   }
   void     computeSlope() {
      const int distanceInBars=iBarShift(_Symbol,0,m_startDt)-iBarShift(_Symbol,0,m_endDt);
      m_slope = (m_end-m_start)/distanceInBars;
   }

   double  getTrendLineValueByTime(const datetime time) {
      if(m_slope==0.)
         computeSlope();
      const int distanceInBarsFromEnd=iBarShift(_Symbol,0,time)-iBarShift(_Symbol,0, m_endDt);
      const double result=m_end-slope*distanceInBarsFromEnd;
      return result;
   }
};

so you will use it in the following way:

void OnTick() {
   TrendLine trendLine;
   string objName;
   for(int i=ObjectsTotal()-1;i>=0;i--) {
      objName=ObjectName(i);
      if(ObjectType(objName)!=OBJ_TREND) continue;
      trendLine.Init(objName);
   }
   datetime t = iTime(_Symbol,0,1);// let's suppose we need TL value for last bar
   double tlValue = trendLine.getTrendLineValueByTime(t);
   Print(__LINE__," ",__FILE__," trend line at time = ",t," = ",DoubleToString(tlValue,8));
}

How to detect when a trend line crosses the MA curve

1 Answers