StatTimeSerAnalysis.ARYuleWalkerFit Method

#	Name	Description
1	Data	Time series.
2	Phi	Returns estimates for Phi coefficients. AR(p) order is determined by Phi length.
3	Sigma2	Returns estimate for Sigma^2 i.e. (AR) model variance.
4	StdErrs	If not nil, it returns estimated phi coefficients standard errors.

Result: stored in self (calling object)

CopyUses MtxExpr, StatTimeSerAnalysis, Math387;
procedure Example;
var ts,phi: Vector;
s2: double;
begin
    ts.LoadFromFile('timeser.vec');
    phi.Length := 3; // for AR(3) process
    ARYuleWalkerFit(ts,phi,s2);
end;