! Mixture distribution model for MZ & DZ misclassification G1: Model parameters Data Calc NGroups=3 Begin Matrices; H Full 1 1 Q Full 1 1 M Full 1 1 Free X Lower 1 1 Free Y Lower 1 1 Free Z Lower 1 1 Free W Lower 1 1 End Matrices; ! parameters are fixed by default, unless declared free Matrix H .5 Matrix Q .25 Start .6 All Begin Algebra; A= X*X'; C= Y*Y'; E= Z*Z'; D= W*W'; N=M|M_M|M; End Algebra: End G2: MZ twin pairs Data NInput_vars=3 Nmodel=2 Labels t1 t2 r Rectangular File=sim1.mz Select t1 t2; Matrices= Group 1 P Full 2 1 End Matrices; Matrix P .95 .05 ! probabilities of being MZ and DZ, respectively Means N; Covariances A+C+D+E | A+C+D _ A+C+D | A+C+D+E _ A+C+D+E | H@A+C+Q@D _ H@A+C+Q@D | A+C+D+E ; Weights P; Options RSidual End G3: DZ twin pairs Data NInput_vars=3 Nmodel=2 Labels t1 t2 r Rectangular File=sim1.dz Select t1 t2; Matrices= Group 1 P Full 2 1 End Matrices; Matrix P .95 .05 ! probabilities of being DZ and MZ, respectively Means N; Covariances A+C+D+E | H@A+C+Q@D _ H@A+C+Q@D | A+C+D+E _ A+C+D+E | A+C+D _ A+C+D | A+C+D+E ; Weights P; Intervals a 1 1 1 c 1 1 1 e 1 1 1 Options RSidual NDecimals=4 End