/*[[
	Name := tseries forecast
	Author := Copyright © 2004, Nick Bilak
	Link := 
	Notes := 
	Separate Window := No
	First Color := Yellow
	First Draw Type := Line
	First Symbol := 160
	Use Second Data := No
	Second Color := DimGray
	Second Draw Type := Line
	Second Symbol := 218
]]*/
Inputs: ndot(21);
var: ka(0),kb(0),sx(0),sy(0),sxy(0),sx2(0),cnt(0),loopBegin(0),shift(0),ival(0);
var: prevbars(0),is_First(true);

SetLoopCount(0);

// Check for additional bars loading or total reloadng.
If Bars<prevbars or Bars-prevbars>1 Then is_First=True;
prevbars=Bars;
//--------------------------------------------------------

// Pre-Loop setup
// loopbegin prevents counting of previously plotted bars excluding current Bars
if is_First Then Begin
   LoopBegin=bars-ndot-2;
   is_First=False;
End;
//--------------------------------------------------------

loopBegin++; // Plot the current bar also
// loop from first bar to current bar (with shift=0)
For shift=loopBegin Downto 0 Begin
	sy=0;
	sx=0;
	sxy=0;
	sx2=0;
	For cnt=1 To ndot Begin
		sy+=close[shift+cnt-1];
		sx+=cnt;
		sx2+=cnt*cnt;
		sxy+=close[shift+cnt-1]*cnt;
	End;
	kb=(ndot*sxy-sx*sy)/(ndot*sx2-sx*sx);
	ka=(sy-kb*sx)/ndot;
	ival=ka+kb;
	SetIndexValue(shift, ival);
	loopBegin--;   // Prevent repeating previously plotted bars on next tick
End;