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If I have more than 3 levels for my ordinal variables then I have N-1 increments?

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If I have more than 3 levels for my ordinal variables then I have N-1 increments?

Hi! guys,

I am doing the threshold model for ordinal variables. and I finished the variables for 3 levels. However, I need modify the script to another variable which contain more 5 levels. I sucess with saturated model wiithout increments It gives me 18 parameters : rMZ,rDZ,4 threshold for MZ1 4 threshold for MZ2,4 threshold for DZ1 and 4 threshold for DZ2,respectively. But I was stuck at ADE model. Some problems in increments.

My script like this:

# Set Starting Values

thVals corValsM corValsD

# SATURATED MODEL:
# Matrices for expected Means & Thresholds (on liabilities) in MZ & DZ twin pairs
MeanG meanG threMZ threDZ corMZ corDZ

# Data objects for Multiple Groups
dataMZ dataDZ

# Objective objects for Multiple Groups
objMZ objDZ

# Combine Groups
groupMZ groupDZ minus2ll obj ciCor ciThre twinSatModel

# -----------------------------------------------------------------------
# RUN SATURATED MODEL (Tetrachoric correlations)
# -----------------------------------------------------------------------
twinSatFit twinSatSumm round(twinSatFit@output$estimate,4)
twinSatSumm

###It works.

####FOR ACEmodel:
athA pathC pathE

# Matrices generated to hold A, C, and E computed Variance Components
covA covC covE

# Matrix & Algebra for expected means vector and expected thresholds

mean Inc

thresh values=c(-0.226,0.127,0.736,1.892),
lbound=c(-3,.001),
labels=c("t1","inc21","inc32","inc43"),
name="Thre")

threshold

# Algebra to compute total variances and standard deviations (diagonal only)
covP

# Algebras generated to hold Parameter Estimates and Derived Variance Components

rowVars colVars estVars

# Algebra for expected Mean and Variance/Covariance Matrices in MZ & DZ twins

covMZ cbind(A+C , A+C+E)), name="expCovMZ" )
covDZ cbind(0.5%x%A+C , A+C+E)), name="expCovDZ" )

# Constraint on variance of Binary variables

matUnv var1

# Data objects for Multiple Groups
dataMZ dataDZ

# Objective objects for Multiple Groups
objMZ objDZ

# Combine Groups
pars modelMZ modelDZ minus2ll obj AceModel

tableFitStatistics(twinSatFit,aceFitConst)

###it only gives me 5 parameters in ACE model: a11, c11,e11, t1, inc.

I think there must be some thing wrong with Increment.

Does anyone have some good idea about how to fix it? Thank you so much for that!