Title figure out likelihood by hand
NGroups 1
Calculation
Begin Matrices;
 E symm 2 2 ! Expected Covariance Matrix
 H full 1 1 ! One half
 T full 1 1 ! Two
 M full 2 1 ! Mean vector 
 P full 1 1 ! Pi
 X full 2 1 ! Observed Data
End Matrices;


Matrix E
 1 .0 1
Matrix H .5
Matrix M 0 0
Matrix P 3.141592
Matrix T 2
Matrix X 1 2

Begin Algebra;

 O=T*P*\sqrt\det(E); ! Fractional part, 2pi*sqrt(det(e))
 Q=(X-M)'&(E~); ! Mahalanobis Distance
 R=\exp(-H*Q); ! e to the power -.5*Mahalanobis distance
 S=-T*\ln(R%O);! minus twice log-likelihood
 Z=-T*\ln(\pdfnor(X'_M'_E));
End Algebra;

End Group;