demo/SimpleRegression_MatrixRaw.R

In OpenMx: Extended Structural Equation Modelling

#
#   Copyright 2007-2019 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.
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#        http://www.apache.org/licenses/LICENSE-2.0
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# -----------------------------------------------------------------------------
# Program: SimpleRegression_MatrixRaw.R  
# Author: Ryne Estabrook
# Date: 2009.08.01 
#
# ModelType: Regression
# DataType: Continuous
# Field: None
#
# Purpose:
#      Simple Regression model to estimate effect of 
#      independent on dependent variables
#      Matrix style model input - Raw data input
#
# RevisionHistory:
#      Hermine Maes -- 10 08 2009 updated & reformatted
#      Ross Gore -- 06 06 2011	added Model, Data & Field metadata
#      Hermine Maes -- 2014.11.02 piecewise specification
# -----------------------------------------------------------------------------

require(OpenMx)
# Load Library
# -----------------------------------------------------------------------------

data(myRegDataRaw)
SimpleDataRaw <- myRegDataRaw[,c("x","y")]
# Prepare Data
# -----------------------------------------------------------------------------

dataRaw      <- mxData( observed=SimpleDataRaw, type="raw" )
matrA        <- mxMatrix( type="Full", nrow=2, ncol=2, 
                          free=c(F,F,T,F), values=c(0,0,1,0), 
                          labels=c(NA,NA,"beta1",NA), byrow=TRUE, name="A" )
matrS        <- mxMatrix( type="Symm", nrow=2, ncol=2, 
                          free=c(T,F,F,T), values=c(1,0,0,1), 
                          labels=c("varx",NA,NA,"residual"), byrow=TRUE, name="S" )
matrF        <- mxMatrix( type="Iden", nrow=2, ncol=2, name="F" )
matrM        <- mxMatrix( type="Full", nrow=1, ncol=2, 
                          free=c(T,T), values=c(0,0), 
                          labels=c("meanx","beta0"), name="M")
expRAM       <- mxExpectationRAM("A","S","F","M", dimnames=c("x","y"))
funML        <- mxFitFunctionML()
uniRegModel  <- mxModel("Simple Regression Matrix Specification", 
                        dataRaw, matrA, matrS, matrF, matrM, expRAM, funML)
# Create an MxModel object
# -----------------------------------------------------------------------------
     
uniRegFit<-mxRun(uniRegModel)
# Fit the model with mxRun
# -----------------------------------------------------------------------------

summary(uniRegFit)
# Print a summary of the results
# -----------------------------------------------------------------------------

uniRegFit$output
# Print the outputs populated by mxRun
# -----------------------------------------------------------------------------

omxCheckCloseEnough(coef(uniRegFit)[["beta0"]], 2.5478, 0.001)
omxCheckCloseEnough(coef(uniRegFit)[["beta1"]], 0.4831, 0.001)
omxCheckCloseEnough(coef(uniRegFit)[["residual"]], 0.6652, 0.001)
omxCheckCloseEnough(coef(uniRegFit)[["meanx"]], 0.0542, 0.001)
omxCheckCloseEnough(coef(uniRegFit)[["varx"]], 1.1053, 0.001)
# Compare OpenMx results to Mx results 
# -----------------------------------------------------------------------------