Adding multiple covariates to ACE model (practical day 3)

Hi,
I wanted to know how I can set up more than one covariate in the script we used for practical day 3 oneSACEvcrH.R
Would I just add lines to the chunk for the covariates? Is there anything downstream in the script that is affected?
############ Create Data Objects for Multiple Groups including Observed Phenotypes and Covariates

dataMZ ← mxData( observed=subset(tDat, zyg==1, c(selVars,covVars)), type=“raw” )

dataDZ ← mxData( observed=subset(tDat, zyg==2, c(selVars,covVars)), type=“raw” )

############ Create Matrices for Covariates and linear Regression Coefficients

defSex ← mxMatrix( type=“Full”, nrow=1, ncol=2, free=FALSE, labels=c(“data.sex1”,“data.sex2”), name=“defSex” )

defAge ← mxMatrix( type=“Full”, nrow=1, ncol=1, free=FALSE, labels=c(“data.age”), name=“defAge” )

betaS ← mxMatrix( type=“Full”, nrow=1, ncol=1, free=TRUE, labels=“bS”, name=“betaS” )

betaA ← mxMatrix( type=“Full”, nrow=1, ncol=1, free=TRUE, labels=“bA”, name=“betaA” )

############ Create Algebra for expected Mean Matrices

meanMZ ← mxMatrix( type=“Full”, nrow=1, ncol=ntv, free=TRUE, values=svm, labels=c(“mMZ1”,“mMZ2”), name=“meanMZ” )

meanDZ ← mxMatrix( type=“Full”, nrow=1, ncol=ntv, free=TRUE, values=svm, labels=c(“mDZ1”,“mDZ2”), name=“meanDZ” )

emeanMZ ← mxAlgebra( expression= meanMZ +betaS%*%defSex +betaA%*%cbind(defAge,defAge), name=“emeanMZ” )

emeanDZ ← mxAlgebra( expression= meanDZ +betaS%*%defSex +betaA%*%cbind(defAge,defAge), name=“emeanDZ” )