Hello!,

I have prepared a script to compute a factor model (path diagram for Phillips and Fulker model ) of phenotypes of parents and twin children given by Neale.

I get an error message indicating the following sentence:

+ mxAlgebra( expression= (A%*%(S%*%t(C)))+(C%*%(t(S)%*%t(A))), name="J" ),

# MZ Twin

- mxAlgebra( expression= (A%&%G%)+(C%&%R%)+J+(N%*%t(N)), name="U1" ),

Error: unexpected '&' in:

"mxAlgebra( expression= (A%*%(S%*%t(C)))+(C%*%(t(S)%*%t(A))), name="J" ),

mxAlgebra( expression= (A%&%G%)+(C%&"

> mxAlgebra( expression= H%x%(A%&%(G+H%x%(T%&%(t(D)+D)))+(C%&%R)+J+((H%x%H)%x%(N%*%t(N))), name="V" ),# DZ Twin
Error: unexpected ',' in "mxAlgebra( expression= H%x%(A%&%(G+H%x%(T%&%(t(D)+D)))+(C%&%R)+J+((H%x%H)%x%(N%*%t(N))),"

>

> # Algebra - Constraints

> #===========================================================

># Phenotypic Variance constraint

> mxAlgebra( expression= A&G+C&R+E%

*%t(E)+A%*%S%

*%t(C)+C%*%t(S)%

*%t(A)+N%*%t(N), name="Z1" )

Error: unexpected ',' in "mxAlgebra( expression= A&G+C&R+E%

*%t(E)+A%*%S%

*%t(C)+C%*%t(S)%

*%t(A)+N%*%t(N), name="Z1" ),"

> mxConstraint(as.mxMatrix(P)==as.mxMatrix(Z1)),

Error: unexpected ',' in "mxConstraint(as.mxMatrix(P)==as.mxMatrix(Z1)),"

========================================================= FIN

I think that the following operations are supported in mxAlgebra:

t( ), %*%, %x% and %&%.

Can the openMx team give me some advice ? Thank you in advance! :-)

Best Regards,

Maikol