data
|
The dataset (including the covariate values). |
timeintervals
|
The name of the column containing the intervals between measurement occasions. The default is NULL, which means that the measurement occasions are assumed to be equidistant. |
identifier
|
The name of the column containing the subject identifiers. |
n_state
|
The number of states that was used for the estimation with step1(). |
postprobs
|
The posterior state-membership probabilities of step2(). |
transitionCovariates
|
The covariate(s) for the transition intensities. The default is NULL, which means that no covariate effects are estimated. |
initialCovariates
|
The covariate(s) for the initial state probabilities. The default is NULL, which means that no covariate effects are estimated. |
n_starts
|
The number of random start sets (for details, see Supplementary Material S.5.4). The default is 25. |
n_initial_ite
|
The number of initial iterations that should be performed for each start set. The default is 10. |
method
|
The estimation method. The default is "BFGS", which is usually faster and more stable when including covariates. The alternative is "CG". |
max_iterations
|
The maximum number of iterations after which the estimation stops regardless of whether convergence has been reached or not. The default is 1000. |
tolerance
|
The convergence tolerance (for details, see Supplementary Material S.5.3). The default is 1e-10. When the message occurs that the model has likely not converged because the Hessian is not positive definite, it is advisable to set the argument to a lower value and repeat the analysis (e.g., 1e-16; Jackson, 2011). |
scaling
|
A scaling parameter for the loglikelihood that can prevent numerical problems from occurring, which is internally passed to the optimization function optim(). An appropriate scale value is close to -2 times the loglikelihood, but the loglikelihood is of course unknown prior to estimating the model. Therefore, by default, lmfa uses an approximation, which is based on the loglikelihood value of a CT-LMM without transitions. Next to this default (i.e., scaling = "proxi"), it is also possible to specify own scale values. |