| Type: | Package | 
| Title: | Measurement Model of Derivatives in 'OpenMx' | 
| Version: | 1.1.0 | 
| Description: | Provides a convenient interface in 'OpenMx' for building Estabrook's (2015) <doi:10.1037/a0034523> Measurement Model of Derivatives (MMOD). | 
| License: | Apache License 2.0 | 
| Encoding: | UTF-8 | 
| LazyData: | true | 
| Imports: | OpenMx | 
| Suggests: | knitr, rmarkdown, testthat, tidyverse | 
| VignetteBuilder: | knitr | 
| RoxygenNote: | 7.1.1 | 
| Depends: | R (≥ 2.10) | 
| NeedsCompilation: | no | 
| Packaged: | 2021-05-18 15:24:22 UTC; khusmann | 
| Author: | Kyle D. Husmann [aut, cre], Timothy R. Brick [aut], Ryne Estabrook [aut] | 
| Maintainer: | Kyle D. Husmann <kdh38@psu.edu> | 
| Repository: | CRAN | 
| Date/Publication: | 2021-05-18 15:40:02 UTC | 
Generate GOLD contrasts
Description
Code from Deboeck (2010)
Usage
ContrastsGOLD(T, max)
Arguments
| T | timeseries | 
| max | max derivatives | 
Create an MMOD
Description
This function builds a Measurement Model of Derivatives (MMOD; Estabrook 2015) with a given factor structure.
Usage
mxMmodModel(
  data,
  modelName,
  idvar,
  timevar,
  structure,
  orthogonal = F,
  embed_dim = NULL,
  fiml = F
)
Arguments
| data | a data frame with measurements in long format | 
| modelName | name for the resulting model | 
| idvar | name of column for subject IDs | 
| timevar | name of column for measurement occasion | 
| structure | factor structure, see 'Details' | 
| orthogonal | if true, fix correlations between factors to 0 (A factor and its derivatives will still intercorrelate) | 
| embed_dim | time delay embedding dimension | 
| fiml | if true, use raw data to fit model with FIML. Otherwise, fit using cov matrix (dropping missing values if necessary). | 
Details
The structure argument is a list of latent factors and their mappings to manifest
variables. For example, a one factor structure would be:
list(F1 = c('m1', 'm2', 'm3', 'm4', 'm5', 'm6'))
And a two factor structure would be:
list(F1 = c('m1', 'm2', 'm3'), F2 = c('m4', 'm5', 'm6'))
Value
an MMOD as an mxModel object
Examples
data(nlsy97depression)
# Fit one factor MMOD
structure <- list(
  F1 = c('nervous', 'down', 'depressed', 'calm', 'happy')
)
mmod_model <- mxMmodModel(data=nlsy97depression,
                          modelName='1 Factor MMOD',
                          idvar='pid', timevar='occasion', structure=structure)
mmod_fit <- OpenMx::mxRun(mmod_model)
summary(mmod_fit)
NLSY97 Longitudinal Depression Scale Data
Description
A 5-item depression scale used on the National Longitudinal Survey of Youth, 1997 sample (NLSY97). Individuals were assessed in 2000, 2002, and 2004. All items are assessed on a 4-point likert scale.
Usage
nlsy97depression
Format
A data frame with 26952 rows and 7 variables:
- pid
- Unique ID of participant 
- sex
- Sex of participant 
- birth_m
- Birth Month 
- birth_y
- Birth Year 
- occasion
- Measurement occasion 
- nervous
- How often participant felt 'like a nervous person' 
- calm
- How often participant felt 'calm and peaceful' 
- down
- How often participant felt 'down or blue' 
- happy
- How often participant felt 'like a happy person' 
- depressed
- How often participant felt 'depressed' 
Source
https://www.bls.gov/nls/nlsy97.htm
Generate Time Delay Embeddings
Description
Generate Time Delay Embeddings
Usage
time_delay_embed(data, idvar, timevar, n_embed)
Arguments
| data | a data frame with measurements in long format | 
| idvar | name of column for subject IDs | 
| timevar | name of column for measurement occasion | 
| n_embed | embedding dimension |