Estimate pop cov matrix of X&Y, with Y observed iff Y>0 Data ng=1 ni=2 vl file=selony.vl Begin Matrices; a sy 2 2 free ! covariance of x,y m fu 1 2 free ! mean of x,y End Matrices; Means M / Covariance A / matrix a 1 .3 1 bound .1 2 a 1 1 a 2 2 option rs mu Option issat end fix all matrix 1 a 1 .5 1 matrix 1 m 0 0 end