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#
# Copyright 2007-2021 by the individuals mentioned in the source code history
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
library(OpenMx)
S <- matrix(
c(2,1,1,1,2,1,1,1,2),
ncol=3,nrow=3,
dimnames=list(c("V1","V2","V3"),c("V1","V2","V3"))
)
W <- diag(6)
mxdataobj <- mxData(S, numObs = 100, means = NA,
type = "acov",acov=W, fullWeight=W)
factormod <- mxModel(
"1factor",
mxdataobj,
mxMatrix(type="Full",nrow=3,ncol=1,free=T,values=0.1,name="Lambda"),
mxMatrix(type="Stand",nrow=1,ncol=1,free=F,values=1,lbound=-1,ubound=1,name="Rxx"),
mxMatrix(type="Diag",nrow=3,free=T,values=diag(S),lbound=0.0001,name="Psi2"),
mxAlgebra( (Lambda%*%Rxx%*%t(Lambda)) + Psi2, name="xpecCov"),
mxAlgebra(sqrt(diag2vec(xpecCov)), name="SDs"),
mxAlgebra(
Lambda / SDs, name="standardizedLoadings"),
mxExpectationNormal(
covariance="xpecCov",
dimnames=colnames(S)),
mxFitFunctionWLS(type="WLS")
)
factorfit <- mxRun(factormod)
summary(factorfit)
omxCheckCloseEnough(as.vector(mxEval(Lambda,factorfit,T)),c(1,1,1),1e-6)
omxCheckCloseEnough(as.vector(mxEval(diag2vec(Psi2),factorfit,T)),c(1,1,1),1e-3)
#---
omxCheckError(mxRun(mxModel(factormod, mxData(S, numObs = 100, means = NA,
type = "acov",acov=W))),
"MxComputeStandardError: terribly sorry, master, but '1factor.data' does not include the asymptotic covariance matrix hence standard errors cannot be computed")
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