kmmasoud <kmmasoud@xxxxxxxxxxxx> wrote:  
  For the top charts in blue do a search in the archives for Dimitris  Tsokakis and Parabolics. There are a number of posts and AFL formulae  for this. I think this may been around 2003/2004, not sure.  
  This is one his last formulae for the parabolic curve:  
  *****  
  //Historical best-fit parabolics
  Plot(C,"C",1,64);
  perc=3;//sensitivity calibration
  x=BarIndex();xx=SelectedValue(x);
  t1=SelectedValue(ValueWhen(PeakBars(H,perc)==0,x));
  H1=SelectedValue(ValueWhen(PeakBars(H,perc)==0,H));
  t11=SelectedValue(ValueWhen(TroughBars(L,perc)==0,x));
  H11=SelectedValue(ValueWhen(TroughBars(L,perc)==0,L));
  g=t1>t11;
  shape=IIf(g,shapeDownArrow*(x==t1),shapeUpArrow*(x==t11));
  Color=IIf(g,colorRed,colorBrightGreen);
  PlotShapes(shape,color);
  t=IIf(g,x-t1,x-t11);
  diff1=IIf(g,H1*(xx-t1),H11*(xx-t11));
 
 Lma=SelectedValue(MA(C,50));
  f1=0;f2=IIf(Lma<100,1,0)+3*int(log10(Lma));
  fa=0;fb=0;step=f2/100;
  for(f=f1;f<f2;f=f+step)
  {
  parabolic=IIf(g,H1-f*t^2,H11+f*t^2);
  S1=SelectedValue(Sum(abs(parabolic-H),xx-t1));
  S11=SelectedValue(Sum(abs(parabolic-L),xx-t11));
  diff=IIf(g,S1,S11);
  if(diff<diff1)
  {
  diff1=diff;fa=f;
  }
  }
  for(f=Max(fa-step,0);f<fa+step;f=f+0.01*step)
  {
  parabolic=IIf(g,H1-f*t^2,H11+f*t^2);
  S1=SelectedValue(Sum(abs(parabolic-H),xx-t1));
  S11=SelectedValue(Sum(abs(parabolic-L),xx-t11));  
  diff=IIf(g,S1,S11);
  if(diff<diff1)
  {
  diff1=diff;fb=f;
  }
  }
  p=IIf(g,H1-fb*t^2,H11+fb*t^2);  
  Plot(IIf(x>=Max(t1,t11),p,-1e10),"",color,1);
  Title=Name()+", "+WriteIf(t1>t11,"f_desc","f_asc")+"="+WriteVal
  (fb,1.4);//+"[f2="+WriteVal(f2)+",step="+WriteVal(step);
  GraphXSpace=3;  
  *****  
  Regards  
 
 ChrisB