bc2: bc2
In Shahin-Roshani/BC2: Fitting multivariate semi-continuous proportionally constrained two-part fixed effects models

Description Usage Arguments Details Value Author(s) References See Also

View source: R/bc2.R

Function for fitting Multivariate semi-continuous proportionally constrained two-part fixed effects model.

bc2(
  logistic,
  positive1,
  positive2,
  data,
  search.space = NULL,
  control.pars = NULL,
  parallel = F,
  core.nums = NULL,
  g.funs = NULL
)

`logistic`	A one sided formula with only right hand side describing the predictors to be included in the logistic part of the model.
`positive1`	A formula describing the response and predictors to be used as the first positive part of the model.
`positive2`	A formula describing the response and predictors to be used as the second positive part of the model.
`data`	Data containing responses and predictors.
`search.space`	A named list containing usual parameters for controlling the optimization process of log-likelihood function. All combinations of the given values in the list will be considered. Valid arguments inside the list are: `coeffs.start`: Numeric vector containing values to be used as starting points of intercepts (a0, a1, a2), coefficients and constraints (b1 & b2) during optimization. `sigmas.start`: Numeric vector containing values to be used as starting points of sigma1 & sigma2 during optimization. `ro.start`: Numeric vector containing values to be used as starting points of ro during optimization. `ro.start`: Optimization methods to be tested for optimizing the log-likelihood function. `iterations`: Number of iterations to achieve the convergence in optimization process. Default is `NULL` where a pre-defined search space will be used. See part 1 in Details.
`control.pars`	Additional control parameters used by optim function. Default is `NULL`. See Details section in `?optim`.
`parallel`	Logical indicating whether optimization of different combinations in search.space must be done in parallel mode or not. Default is `FALSE`.
`core.nums`	Number of CPU cores to be used for parallel computation. Default is `NULL` where half of the CPU cores will be used. See `?detectCores`.
`g.funs`	A single function or a list of length two containing the functions to be used for transforming non-zero responses. If `g.funs` were specified by user, `$Data` part of return object will contain the un-transformed responses while structured data part will include transformed responses based on functions in `g.funs`.

When search.space is NULL, a pre-defined search space will be used which is:

list(coeffs.start=seq(-1,1,1),

     sigmas.start=c(.1,1),

     ro.start=c(-.5,.5),

     methods=c('Nelder-Mead','BFGS'),

     iterations=c(100,500))

S3 print class of method 'bc2' which is A list of length 3 containing fitting information of the logistic and the two positive parts.

This list is a part of a more comprehensive return that can be accessed when the fit is saved in an object. The full return set contains:

$Data: Cleaned data-set with original and un-transformed responses. Also see g.funs argument.
$`Structured data`: A list of divided and cleaned data to be used in the fitting process. If g.funs were specified, transformed responses will be included in this part.
$`Optimization info`: A tibble containing information about evaluation of different combinations that was given in search.space for optimization.
$`Best combination`: The best combination of parameters that results in the best set of estimations.
$`Final tables`: The default print output of class bc2 that was mentioned earlier.