Calculate power for the 'time x treatment' effect
in two- and three-level multilevel longitudinal studies with missing data.
Both the third-level factor (e.g. therapists, schools, or physicians),
and the second-level factor (e.g. subjects), can be assigned random slopes.
Studies with partially nested designs, unequal cluster sizes,
unequal allocation to treatment arms, and different dropout patterns
per treatment are supported. For all designs power can be
calculated both analytically and via simulations. The analytical
calculations extends the method described in Galbraith et al. (2002)
<doi:10.1016/S0197-2456(02)00205-2>, to three-level models.
Additionally, the simulation tools provides flexible ways to investigate
bias, Type I errors and the consequences of model misspecification.

Sample Size Analysis for Psychological Networks and More
person(given = "Mihai",
family = "Constantin",
role = c("aut", "cre"),
email = "mihai@mihaiconstantin.com",
comment = c(ORCID = "0000-0002-6460-0107"))
An implementation of the sample size computation method for network
models proposed by Constantin et al. (2021) <doi:10.31234/osf.io/j5v7u>
The implementation takes the form of a three-step recursive algorithm
designed to find an optimal sample size given a model specification and a
performance measure of interest. It starts with a Monte Carlo simulation
step for computing the performance measure and a statistic at various sample
sizes selected from an initial sample size range. It continues with a
monotone curve-fitting step for interpolating the statistic across the entire
sample size range. The final step employs stratified bootstrapping to quantify
the uncertainty around the fitted curve.
R6, progress, parallel, splines2, quadprog, osqp, bootnet,
qgraph, ggplot2, patchwork
'Backend.R' 'Basis.R' 'Model.R' 'GgmModel.R' 'Interpolation.R'
'Spline.R' 'StepThree.R' 'StepTwo.R' 'Statistic.R'
'PowerStatistic.R' 'StatisticFactory.R' 'ModelFactory.R'
'StepOne.R' 'Range.R' 'Method.R' 'OsqpSolver.R'
'QuadprogSolver.R' 'Solver.R' 'SolverFactory.R' 'Validation.R'
'constants.R' 'exports.R' 'helpers.R' 'logo.R'
'powerly-package.R'
Mihai Constantin [aut, cre] (<https://orcid.org/0000-0002-6460-0107>)